"Rocky" - 1981 F250 Restoration

[taskswap]

I understand biting off as much as one can chew. I seem to always have a mouth full.

But stripping the camper sounds like a big task. Have you thought about spraying the framing with foam insulation after you put the exterior siding on but before you put the interior paneling on? That might give it a bit more strength and even more insulation.

On the winch, I like that tray. And there is plenty of room under there to mount it. But I agree with you, some reinforcement seems appropriate. But you might consider buying a small welder. It would sure be handy to be able to put things in place and at least tack them, if not do all the welding yourself.

Also, I'm thinking someone on here put a winch behind the stock bumper, but I didn't find it in a search I did. Perhaps you can as it might save you a bit of trouble. But it worked out nicely from what I remember. And I think he put the fairlead in the spot for the front tag.

As for chiming in on my project, I understand. But I got word back from the manufacturer that my relay idea will work. So now I'm searching for the right "relay", and if you have any guidance I'd appreciate it, here.

Done/replied. Again, not sure it's helpful, that relay looks great, but I said what I said. :)

As for the camper, yes, I've considered it, but it's probably a waste of money in terms of insulating value to be honest. It's a pop-top canvas camper. Here's the same model in much better shape, for the curious:

Anything a Mr Buddy heater can't keep up with, some wall insulation isn't going to help. HOWEVER I might consider doing it for structural reasons. Foamed walls are more rigid and this thing's been around the block in a lot of ways. From the front, the main "box" (which is the primary load-bearing structure) is pretty sound. In the bottom of the box, Starcraft built these around a steel frame, and that part's held up OK:

But the "wings" are a hot mess, particularly on the right side. They're just 2x2 + OSB construction so any water damage just turns them to mush. Which you know, campers, you nick some molding on a tree and water's going to get in... To make matters worse, Starcraft went seriously cheap on these things. If you've ever seen a nice slide-in you can eject that straight from your head. Think more "just HOW cheaply can I do this?" and then really challenge yourself and you have the idea, LOL.

For instance, you know how most slide-ins have corner jacks to get them out? Well this has jacks. Just not at the corners. It has THREE jacks. Two on the left side (the "heavy" side) and ONE in the center of the right, like a tripod. Each jack is rated for 500lbs and the camper weighs almost exactly 1500 so it was bare minimum to begin with. A common thing many folks did is add a fourth side jack plate, and the previous owner obviously did this, but badly, just carriage-bolted into the OSB. Predictably, that's all crushed and torn out now.

There's also some "stupid" when it comes to this design. There's an access door in exactly the center of the bottom left/right sides of the camper. Precisely where the wheel wells are on an 8' bed - and this camper requires an 8' bed. That means you have no access to useful storage in front of your wheel wells, but you do have useless, drafty, mouse-inviting doors that never quite seal well on the sides.

My plan is to get Rocky minimally driveable so I can put a pause on that project, then go get the camper and get it into our garage. It'lll just barely fit, but there's no way I'm working on this thing outside. With the winds we get sometimes in Colorado, once I start pulling off the siding, the wind will just tear it apart otherwise.

I'm going to tear it down to its skeleton and fix the structural issues, then re-assemble it but with fiberglass siding instead.

So if I go quiet in January/February that's what I'm doing!

[Gary Lewis]

Done/replied. Again, not sure it's helpful, that relay looks great, but I said what I said. :)

As for the camper, yes, I've considered it, but it's probably a waste of money in terms of insulating value to be honest. It's a pop-top canvas camper. Here's the same model in much better shape, for the curious:

Anything a Mr Buddy heater can't keep up with, some wall insulation isn't going to help. HOWEVER I might consider doing it for structural reasons. Foamed walls are more rigid and this thing's been around the block in a lot of ways. From the front, the main "box" (which is the primary load-bearing structure) is pretty sound. In the bottom of the box, Starcraft built these around a steel frame, and that part's held up OK:

But the "wings" are a hot mess, particularly on the right side. They're just 2x2 + OSB construction so any water damage just turns them to mush. Which you know, campers, you nick some molding on a tree and water's going to get in... To make matters worse, Starcraft went seriously cheap on these things. If you've ever seen a nice slide-in you can eject that straight from your head. Think more "just HOW cheaply can I do this?" and then really challenge yourself and you have the idea, LOL.

For instance, you know how most slide-ins have corner jacks to get them out? Well this has jacks. Just not at the corners. It has THREE jacks. Two on the left side (the "heavy" side) and ONE in the center of the right, like a tripod. Each jack is rated for 500lbs and the camper weighs almost exactly 1500 so it was bare minimum to begin with. A common thing many folks did is add a fourth side jack plate, and the previous owner obviously did this, but badly, just carriage-bolted into the OSB. Predictably, that's all crushed and torn out now.

There's also some "stupid" when it comes to this design. There's an access door in exactly the center of the bottom left/right sides of the camper. Precisely where the wheel wells are on an 8' bed - and this camper requires an 8' bed. That means you have no access to useful storage in front of your wheel wells, but you do have useless, drafty, mouse-inviting doors that never quite seal well on the sides.

My plan is to get Rocky minimally driveable so I can put a pause on that project, then go get the camper and get it into our garage. It'lll just barely fit, but there's no way I'm working on this thing outside. With the winds we get sometimes in Colorado, once I start pulling off the siding, the wind will just tear it apart otherwise.

I'm going to tear it down to its skeleton and fix the structural issues, then re-assemble it but with fiberglass siding instead.

So if I go quiet in January/February that's what I'm doing!

Yes, I see what you mean about insulation not being very effective.

But the foam might provide some strength, although there may be easier ways to do that, like with a thin sheet of plywood. And no OSB! Man, that is a problem waiting to happen.

Sounds like you can significantly improve the integrity and the usefulness of the camper by just a bit a reasonable thinking. Access doors that seal to ahead of the wheel arches would be a big improvement.

As for going quiet, be careful - we've been known to send the local constabulary out to investigate when a regular goes AWOL.

[taskswap]

Yes, I see what you mean about insulation not being very effective.

But the foam might provide some strength, although there may be easier ways to do that, like with a thin sheet of plywood. And no OSB! Man, that is a problem waiting to happen.

Sounds like you can significantly improve the integrity and the usefulness of the camper by just a bit a reasonable thinking. Access doors that seal to ahead of the wheel arches would be a big improvement.

As for going quiet, be careful - we've been known to send the local constabulary out to investigate when a regular goes AWOL.

Never fear. Silence isn't really a skill of mine. Quiet means posting less, not zero, LOL.

Tiny progress but tonight I sorted out the dome light. After replacing the door switches, the dome light still wasn't working. I wasn't really surprised because when I dismantled the dash I pulled out some super sketchy "DIY" wires after taking some photos so I could sort them out later. It was the logical next thing to evaluate:

Sure enough, the courtesy/dome-light circuit didn't have a fuse in it. Then of course I had the scramble where the dome light wouldn't turn OFF, which turned out to be the headlight/dimmer knob being far-counter-clockwise, as it always does, it was just really hard to tell because with the dash off I have no knobs. :) It's shocking how hard that sucker is to turn with pliers when it's so easy with a dinky plastic knob!

Anyway, both door now turn on the dome light. It was then that I discovered just how pathetically dim that dome light is. It's basically useless. I used up all my HiPo LEDs (which are pricey but worth it) on the instrument panel, but had an LED bulb from a camper project from this summer so I threw that in there and it fit OK. It's definitely brighter.

As a splurge item I got one of the dome/map light combos on eBay. Probably half because it's chrome I know my stock setup doesn't have both required wires for this, but since I haven't installed all the trim molding yet this is a good time to add that. Besides, I like to have the extra (fused) always-on wire around that spot so I can add a pickup-bed/cargo light at some point, and be able to turn it on while I'm standing in the bed. This way the wire will be right there.

I also BELIEVE I identified a mystery wire in the driver's side door kick:

Terrible pic, this wire is actually solid brown, and a single-wire connector. The "Wire and Color Codes" guide lists this as any number of circuits but I believe based on the EVTM this is C906, "Cab Marker Lights" (which I don't have installed).

I'm spending a lot of time identifying mystery circuits both because I'm a geek and just want to know, and also so I don't have to open stuff back up once I close it. I'm on the cusp of re-installing the dash, and trying to dot every i before I do...

[Gary Lewis]

Never fear. Silence isn't really a skill of mine. Quiet means posting less, not zero, LOL.

Tiny progress but tonight I sorted out the dome light. After replacing the door switches, the dome light still wasn't working. I wasn't really surprised because when I dismantled the dash I pulled out some super sketchy "DIY" wires after taking some photos so I could sort them out later. It was the logical next thing to evaluate:

Sure enough, the courtesy/dome-light circuit didn't have a fuse in it. Then of course I had the scramble where the dome light wouldn't turn OFF, which turned out to be the headlight/dimmer knob being far-counter-clockwise, as it always does, it was just really hard to tell because with the dash off I have no knobs. :) It's shocking how hard that sucker is to turn with pliers when it's so easy with a dinky plastic knob!

Anyway, both door now turn on the dome light. It was then that I discovered just how pathetically dim that dome light is. It's basically useless. I used up all my HiPo LEDs (which are pricey but worth it) on the instrument panel, but had an LED bulb from a camper project from this summer so I threw that in there and it fit OK. It's definitely brighter.

As a splurge item I got one of the dome/map light combos on eBay. Probably half because it's chrome I know my stock setup doesn't have both required wires for this, but since I haven't installed all the trim molding yet this is a good time to add that. Besides, I like to have the extra (fused) always-on wire around that spot so I can add a pickup-bed/cargo light at some point, and be able to turn it on while I'm standing in the bed. This way the wire will be right there.

I also BELIEVE I identified a mystery wire in the driver's side door kick:

Terrible pic, this wire is actually solid brown, and a single-wire connector. The "Wire and Color Codes" guide lists this as any number of circuits but I believe based on the EVTM this is C906, "Cab Marker Lights" (which I don't have installed).

I'm spending a lot of time identifying mystery circuits both because I'm a geek and just want to know, and also so I don't have to open stuff back up once I close it. I'm on the cusp of re-installing the dash, and trying to dot every i before I do...

Ok, if you keep posting, even small posts, we won't send out the troops to find you.

Good job on the dome light and door switches, which you apparently figured out? And now is the time on the map lights awa always-on circuit. But don't expect much from the cargo light if you install a stock one. I'd think about something aftermarket, although I don't have a recommendation.

Yes, the marker lights wire should be brown, and that's where it should be. You can test that by pulling the light switch on. And you are right about rotating that thing w/o the knob.

Keep on keeping on!

[taskswap]

Good job on the dome light and door switches, which you apparently figured out? And now is the time on the map lights awa always-on circuit. But don't expect much from the cargo light if you install a stock one. I'd think about something aftermarket, although I don't have a recommendation.

I was going to try some kind of aftermarket one. I'm more concerned with visual appeal than performance though, so I'd like to find something chrome and of the era. Even if it means dimmer light. I've never found cargo lights to be all that helpful - even the brightest don't fill an 8' bed with "sunlight". It's just a nice to have. For my real bed lighting I'll be pulling a utility circuit back and installing a switch and some LED strips.

But I do want the map lights so I pulled an always-hot wire up to the dome light box. I bought one of the map/dome combos on eBay that looks in decent shape. I had some green wire that was close to the green/yellow Ford normally uses so I went ahead and used that.

The door locks are powered now. I haven't attached them to the lock rods but the wiring is done and the solenoids (just sitting in the bottoms of the doors for now) move when I hit the button. Since I hate wire taps but didn't want to cut an existing circuit, I used one of those "Add-A-Circuit" fuses, I've had good luck with those before.

I had less success with the radio. I got it all wired but it's not turning on. The previous owner had cut the radio power wire very close to where it spreads out of the main loom, but had left the 4-pin accessory wire that's used for the digital clock / CB. So I figured why not make something up out of that? I cut that accessory wire in half and spliced in a line to the radio and also an accessory plug with a GND/+12V/ACC triplet for some future toy. That's what's in the plastic bag - I put the mating connector and some pins in there and taped it right onto the harness so I can't lose it later when I want it.

That must have been the end of my cleverness though because after finishing the speaker part of the harness, I plugged it all into the radio and... nothing. Not in any key position. I ran out of time playing with it but will break out the meter next chance I get and see what pins might not be right.

That did give me an excuse to find another problem though. I bought one of those intermittent wiper + switch combos and installed that but something's not quite right. It's not intermittent in any of the positions, and no positions turns it "off" so the wipers run constantly.

More progress, more mysteries.

[Gary Lewis]

Good job on the dome light and door switches, which you apparently figured out? And now is the time on the map lights awa always-on circuit. But don't expect much from the cargo light if you install a stock one. I'd think about something aftermarket, although I don't have a recommendation.

I was going to try some kind of aftermarket one. I'm more concerned with visual appeal than performance though, so I'd like to find something chrome and of the era. Even if it means dimmer light. I've never found cargo lights to be all that helpful - even the brightest don't fill an 8' bed with "sunlight". It's just a nice to have. For my real bed lighting I'll be pulling a utility circuit back and installing a switch and some LED strips.

But I do want the map lights so I pulled an always-hot wire up to the dome light box. I bought one of the map/dome combos on eBay that looks in decent shape. I had some green wire that was close to the green/yellow Ford normally uses so I went ahead and used that.

The door locks are powered now. I haven't attached them to the lock rods but the wiring is done and the solenoids (just sitting in the bottoms of the doors for now) move when I hit the button. Since I hate wire taps but didn't want to cut an existing circuit, I used one of those "Add-A-Circuit" fuses, I've had good luck with those before.

I had less success with the radio. I got it all wired but it's not turning on. The previous owner had cut the radio power wire very close to where it spreads out of the main loom, but had left the 4-pin accessory wire that's used for the digital clock / CB. So I figured why not make something up out of that? I cut that accessory wire in half and spliced in a line to the radio and also an accessory plug with a GND/+12V/ACC triplet for some future toy. That's what's in the plastic bag - I put the mating connector and some pins in there and taped it right onto the harness so I can't lose it later when I want it.

That must have been the end of my cleverness though because after finishing the speaker part of the harness, I plugged it all into the radio and... nothing. Not in any key position. I ran out of time playing with it but will break out the meter next chance I get and see what pins might not be right.

That did give me an excuse to find another problem though. I bought one of those intermittent wiper + switch combos and installed that but something's not quite right. It's not intermittent in any of the positions, and no positions turns it "off" so the wipers run constantly.

More progress, more mysteries.

You can put an LED in the factory cargo light, which is chromed plastic, and get a bit more light out of it. Enough to know it is on.

On the wipers, you do know the delay is to the left of Off? Normal speeds to the right. But there's a solder joint that breaks in the delay circuit due to impact of the park brake being popped off. See the page at Documentation/Electrical/Windshield Wipers for repair info.

With power door locks have you considered either a security system or at least a remote locking setup? We have the schematic on here somewhere to install one of the cheap remote locking systems, probably like this one. For less than $20 it sure would make things more convenient.

Neat approach to future-proofing the electrical system. I wish I'd done something like that when I put power up to the Highliner headliner. I put always-on power up there, but not switched power, and the mirror needs both.

 

[taskswap]

You can put an LED in the factory cargo light, which is chromed plastic, and get a bit more light out of it. Enough to know it is on.

Yeah... That was my conclusion as well! I can just barely tell it's on now. I'm going to augment with some under-dash courtesy lights in the form of LED strips as well. That should help a lot.

On the wipers, you do know the delay is to the left of Off? Normal speeds to the right. But there's a solder joint that breaks in the delay circuit due to impact of the park brake being popped off. See the page at Documentation/Electrical/Windshield Wipers for repair info.

I haven't tried that but definitely will. I was a little puzzled why every position of the switch had the wipers on in some capacity, but there's plenty to check.

With power door locks have you considered either a security system or at least a remote locking setup? We have the schematic on here somewhere to install one of the cheap remote locking systems, probably like this one. For less than $20 it sure would make things more convenient.

I should have been more specific, I did install one of those. I got the one from LMC, but it looks like the same vendor (Central Locking), just a different transmitter (no trunk button). That's actually my interim plan until I can source parts for the manual slide-locks, since I've decided to wait it out for those. I'll just mainly use the transmitters, and the slide locks can just be a vanity item "some day".

Neat approach to future-proofing the electrical system. I wish I'd done something like that when I put power up to the Highliner headliner. I put always-on power up there, but not switched power, and the mirror needs both.

Thanks, I hope so. I feel like I never end up using my "future proof" ideas and always finding things I didn't think about. But the effort is small and at least I know it's there! I was tempted to buy the clock as well since they come up on eBay a lot, it's a cool "period" feature. But let's be honest, it's a pretty crappy clock. It's probably not worth what people expect to get for them even as a vanity item.

Another option would be a radio mount. We're not going to be "jeeping it" with this thing, but we do like having trail radios when we camp with friends because it makes it easier to meet up at trail heads and dispersed campgrounds. We have a 5-pack of Baofengs we got on sale one day and I could easily make that a semi-mounted/removeable setup.

Or I may use it for some type of GPS tracker device. The moment a nicer paint job is on this thing it's going to be a theft magnet. I'm going to be installing some additional type of hidden engine-disable circuit like disabling the starter relay or ignition module, I still like the idea of some kind of dash cam / GPS tracker. I have a dash cam in my 5th wheel hauler and it gives me peace of mind that if I crush some moron who cuts me off and slams on the brakes in traffic, I have a record of it. Some of those units do GPS tracking too, and would be a nice lojack-category option.

[Gary Lewis]

You can put an LED in the factory cargo light, which is chromed plastic, and get a bit more light out of it. Enough to know it is on.

Yeah... That was my conclusion as well! I can just barely tell it's on now. I'm going to augment with some under-dash courtesy lights in the form of LED strips as well. That should help a lot.

On the wipers, you do know the delay is to the left of Off? Normal speeds to the right. But there's a solder joint that breaks in the delay circuit due to impact of the park brake being popped off. See the page at Documentation/Electrical/Windshield Wipers for repair info.

I haven't tried that but definitely will. I was a little puzzled why every position of the switch had the wipers on in some capacity, but there's plenty to check.

With power door locks have you considered either a security system or at least a remote locking setup? We have the schematic on here somewhere to install one of the cheap remote locking systems, probably like this one. For less than $20 it sure would make things more convenient.

I should have been more specific, I did install one of those. I got the one from LMC, but it looks like the same vendor (Central Locking), just a different transmitter (no trunk button). That's actually my interim plan until I can source parts for the manual slide-locks, since I've decided to wait it out for those. I'll just mainly use the transmitters, and the slide locks can just be a vanity item "some day".

Neat approach to future-proofing the electrical system. I wish I'd done something like that when I put power up to the Highliner headliner. I put always-on power up there, but not switched power, and the mirror needs both.

Thanks, I hope so. I feel like I never end up using my "future proof" ideas and always finding things I didn't think about. But the effort is small and at least I know it's there! I was tempted to buy the clock as well since they come up on eBay a lot, it's a cool "period" feature. But let's be honest, it's a pretty crappy clock. It's probably not worth what people expect to get for them even as a vanity item.

Another option would be a radio mount. We're not going to be "jeeping it" with this thing, but we do like having trail radios when we camp with friends because it makes it easier to meet up at trail heads and dispersed campgrounds. We have a 5-pack of Baofengs we got on sale one day and I could easily make that a semi-mounted/removeable setup.

Or I may use it for some type of GPS tracker device. The moment a nicer paint job is on this thing it's going to be a theft magnet. I'm going to be installing some additional type of hidden engine-disable circuit like disabling the starter relay or ignition module, I still like the idea of some kind of dash cam / GPS tracker. I have a dash cam in my 5th wheel hauler and it gives me peace of mind that if I crush some moron who cuts me off and slams on the brakes in traffic, I have a record of it. Some of those units do GPS tracking too, and would be a nice lojack-category option.

An engine kill is easy. Since you understand electronics you probably realize that the ignition module grounds and releases the primary side of the coil. And the tach circuit is tied to that same point. What would happen if the tach circuit was grounded?

Starter-kill circuits aren't much help on a manual transmission. So instead of using the normally-closed contact on my security system's relay that opens when the system is armed so the starter won't crank, I used the normally-open contact.

Instead of a GPS tracker, have you read this thread?

My Pormido mirror/dashcam does have a GPS antenna and it'll record where the truck goes. But that's not much use to find the vehicle if it has been stolen. However, assuming the thief is dumb enough to take it some place connected to him, if you get the truck back via an Apple airtag you can then find out where it has been.

[taskswap]

An engine kill is easy. Since you understand electronics you probably realize that the ignition module grounds and releases the primary side of the coil. And the tach circuit is tied to that same point. What would happen if the tach circuit was grounded?

Starter-kill circuits aren't much help on a manual transmission. So instead of using the normally-closed contact on my security system's relay that opens when the system is armed so the starter won't crank, I used the normally-open contact.

Good point. I do know electronics but don't know these older ignition systems very well so hadn't thought of that. Fortunately this vehicle will spend a lot of time in secured storage but every little bit helps while out and about.

Instead of a GPS tracker, have you read this thread?

My Pormido mirror/dashcam does have a GPS antenna and it'll record where the truck goes. But that's not much use to find the vehicle if it has been stolen. However, assuming the thief is dumb enough to take it some place connected to him, if you get the truck back via an Apple airtag you can then find out where it has been.

Are they using AirTags as a security device? Maybe I should add some thoughts to the thread. As a software engineer I would definitely never recommend that.

The thing is, those devices are Bluetooth-based with very limited ranges and no internal GPS functionality. They require a "helper" cell phone to figure out where they are and get their reports out to the world. The magic Apple did was coding into iOS a feature that automatically allows any nearby AirTags to "piggyback" on any phone's data connection for its location and communication requirements whether you own the AirTag or not.

There are a few problems with this approach:

1. A thief would have to have this function activated on their phone for it to work. If they didn't have a modern iPhone or had the feature off, the AirTag would have no way to "report in" where it was. See https://theconversation.com/remember-apple-airtags-and-find-my-app-only-work-because-of-a-vast-largely-covert-tracking-network-160781.

2. Apple's been criticized for privacy concerns (people using AirTags to stalk other people) so they've added privacy features that warn a user there's an AirTag nearby that might be tracking them. (See https://www.makeuseof.com/what-to-do-when-you-see-airtag-found-moving-with-you-alert/)

The idea is to prevent a creep at a bar slipping an AirTag into a victim's purse, car, etc. A thief that DID have a modern iPhone would be alerted that the device was there - not what you want.

IMO if you want an anti-theft device you want it to be completely self contained and not reliant on anything else. That means a sealed unit, GPS, and a cellular connection. It also needs to have a backup battery, because my understanding is a common practice among thieves is to disconnect the battery as soon as possible...

I have Google Fi and you can get "data SIMs" pretty cheap for it, $10 to add to your plan. I'm looking into self-contained units designed specifically for tracking vehicles that can take a SIM. It's not actually a massive priority because most of the time this will be in a secured storage facility or in the back-country (vehicle theft at a trailhead is extremely rare) but it's definitely on the list to deal with at some point...

 

[Gary Lewis]

An engine kill is easy. Since you understand electronics you probably realize that the ignition module grounds and releases the primary side of the coil. And the tach circuit is tied to that same point. What would happen if the tach circuit was grounded?

Starter-kill circuits aren't much help on a manual transmission. So instead of using the normally-closed contact on my security system's relay that opens when the system is armed so the starter won't crank, I used the normally-open contact.

Good point. I do know electronics but don't know these older ignition systems very well so hadn't thought of that. Fortunately this vehicle will spend a lot of time in secured storage but every little bit helps while out and about.

Instead of a GPS tracker, have you read this thread?

My Pormido mirror/dashcam does have a GPS antenna and it'll record where the truck goes. But that's not much use to find the vehicle if it has been stolen. However, assuming the thief is dumb enough to take it some place connected to him, if you get the truck back via an Apple airtag you can then find out where it has been.

Are they using AirTags as a security device? Maybe I should add some thoughts to the thread. As a software engineer I would definitely never recommend that.

The thing is, those devices are Bluetooth-based with very limited ranges and no internal GPS functionality. They require a "helper" cell phone to figure out where they are and get their reports out to the world. The magic Apple did was coding into iOS a feature that automatically allows any nearby AirTags to "piggyback" on any phone's data connection for its location and communication requirements whether you own the AirTag or not.

There are a few problems with this approach:

1. A thief would have to have this function activated on their phone for it to work. If they didn't have a modern iPhone or had the feature off, the AirTag would have no way to "report in" where it was. See https://theconversation.com/remember-apple-airtags-and-find-my-app-only-work-because-of-a-vast-largely-covert-tracking-network-160781.

2. Apple's been criticized for privacy concerns (people using AirTags to stalk other people) so they've added privacy features that warn a user there's an AirTag nearby that might be tracking them. (See https://www.makeuseof.com/what-to-do-when-you-see-airtag-found-moving-with-you-alert/)

The idea is to prevent a creep at a bar slipping an AirTag into a victim's purse, car, etc. A thief that DID have a modern iPhone would be alerted that the device was there - not what you want.

IMO if you want an anti-theft device you want it to be completely self contained and not reliant on anything else. That means a sealed unit, GPS, and a cellular connection. It also needs to have a backup battery, because my understanding is a common practice among thieves is to disconnect the battery as soon as possible...

I have Google Fi and you can get "data SIMs" pretty cheap for it, $10 to add to your plan. I'm looking into self-contained units designed specifically for tracking vehicles that can take a SIM. It's not actually a massive priority because most of the time this will be in a secured storage facility or in the back-country (vehicle theft at a trailhead is extremely rare) but it's definitely on the list to deal with at some point...

That's interesting about the airtag. Hadn't read up on it, but it makes sense. However, I don't know if anyone has tried it or is using it.

As for the ignition, the coil has one side of its primary tied to the battery, albeit through a ballast resistor to reduce the current other than during starting. The ignition module mimics points, where the points close to charge the coil by building up an EMF field. Then the points open when the ignition is supposed to fire and the electromagnetic field falls through the secondary and creates the high voltage that fires the plug. But if the low side of the coil is held to ground then nothing the points or ignition module can do will cause the ignition to fire.

Another option for those of us with electric fuel pumps is to prevent them from running. Plus, you can kill the power feed to the ECU if you have EFI.

And with all or any of that in place it is very unlikely anyone is going to get the truck to run - at least not without someone hearing the blaring siren and, in my case, horn. About all they could do is to open the hood and cut the battery cable, hoping to silence the alarm. But a $20 backup battery will prevent that. Plus, a hood lock will slow them down even more.

As for tracking, your plan sounds good. With the value of these trucks going up dramatically it pays to do what you can to prevent them being stolen or get them back quickly.

And speaking of value, here's what Hagerty says a 1981 F250 regular cab long bed with a 351 is worth. (Yes, I know you have a 400, but Hagerty didn't list that as an option.)