Big Blue's Transformation

[Nothing Special]

I tapped my trigger switch at the location of the 'headlights on' chime.

It's conveniently in the center of the dash by the radio.

The "headlights on" warning is usually triggered by the dash lights rather than the running lights. So if you dim your dash lights enough the warning will go off, even if the running lights (and headlights) are on.

That's a nice feature for the "headlights on" warning because it lets you turn the warning off (by dimming the dash lights) so you can have the headlights on with the key off (and no warning) if you want to.

I'm thinking it's less desirable for a power source for the fog light relay because it wouldn't be an on / off, 12V / 0V signal. It would be a variable voltage. If you dimmed the dash lights enough the fog lights wouldn't come on, and if you had them bright enough they would. But it wouldn't be a straight either / or.

Maybe it would work out fine, but I didn't want to go that route. So I did sort of a approach and spliced into the wire at the left side front marker lamp. That meant running the wire through the firewall to get to the switch. But I put it in a loom with a bunch of other related wires I added, so that wasn't a big deal to me. I'm sure there's a wire at the light switch that would be cleaner to use.

[Gary Lewis]

Hey Gary, you haven't drawn out the wiring diagram for the fog light switch yet have you? Or do you know where you are tying into the parking lamp circuit (if using Bob's idea)? Was looking over the evtm for some other stuff, hit the parking lamp circuit, and just wondered your plan.

Additionally, how are you doing the firewall penetration for all the switch wiring? I was doing some shop cleaning and ran across a part I should have thrown in the box as an option for this but you may have a great approach already.

Jim - Getting the "lights-on" signal from that area an excellent idea! But, that got me to thinking about it and it turns out the same signal goes to the clock, and its wiring is poking into the Mission Control area.

Scott - I think that answers the first question. But that brings me to the second, and much more difficult, question of firewall penetration. And the simple answer is no. So if you have something that would create an option, please let me know.

That is a much more difficult question because I think I've stuffed the grommet for the speedometer cable with several wires that are headed to Mission Control, which packed it pretty tight. And now I believe I'm going to have to change the speedo cable.

The speed control surges. I realized the speedometer reading was wavering, and lubed the lower cable since it was easy, and that helped a little bit. That cable is one that I replaced as the truck went back together, and I remember the speedo wavering well before I pulled it apart, so that cable isn't the culprit.

When I had the instrument cluster out the other day as I was tapping into the fuel gauge wiring for the Meter Match I lubed the upper cable. That helped a bunch on the wavering and the surging, but didn't cure it.

So I'm thinking I'll have to pull the upper cable's outer sheath and replace it. And I'm not sure how hard that will be with the grommet stuffed full of wiring. And if I'm going to run the wires through a different penetration point now is the time since there's nothing connected to the other end and I can pull them back out.

What I haven't done is to change the speed control's transducer. Could it be dragging, causing the wavering and surging?

[Gary Lewis]

I tapped my trigger switch at the location of the 'headlights on' chime.

It's conveniently in the center of the dash by the radio.

The "headlights on" warning is usually triggered by the dash lights rather than the running lights. So if you dim your dash lights enough the warning will go off, even if the running lights (and headlights) are on.

That's a nice feature for the "headlights on" warning because it lets you turn the warning off (by dimming the dash lights) so you can have the headlights on with the key off (and no warning) if you want to.

I'm thinking it's less desirable for a power source for the fog light relay because it wouldn't be an on / off, 12V / 0V signal. It would be a variable voltage. If you dimmed the dash lights enough the fog lights wouldn't come on, and if you had them bright enough they would. But it wouldn't be a straight either / or.

Maybe it would work out fine, but I didn't want to go that route. So I did sort of a http://www.garysgaragemahal.com/uploads/6/5/8/7/65879365/florida-man-42_orig.jpg approach and spliced into the wire at the left side front marker lamp. That meant running the wire through the firewall to get to the switch. But I put it in a loom with a bunch of other related wires I added, so that wasn't a big deal to me. I'm sure there's a wire at the light switch that would be cleaner to use.

Bob - I'm looking at Circuit 14, the brown wire shown below. It doesn't dim, but is just on/off.

[Machspeed]

Jim - Getting the "lights-on" signal from that area an excellent idea! But, that got me to thinking about it and it turns out the same signal goes to the clock, and its wiring is poking into the Mission Control area.

Scott - I think that answers the first question. But that brings me to the second, and much more difficult, question of firewall penetration. And the simple answer is no. So if you have something that would create an option, please let me know.

That is a much more difficult question because I think I've stuffed the grommet for the speedometer cable with several wires that are headed to Mission Control, which packed it pretty tight. And now I believe I'm going to have to change the speedo cable.

The speed control surges. I realized the speedometer reading was wavering, and lubed the lower cable since it was easy, and that helped a little bit. That cable is one that I replaced as the truck went back together, and I remember the speedo wavering well before I pulled it apart, so that cable isn't the culprit.

When I had the instrument cluster out the other day as I was tapping into the fuel gauge wiring for the Meter Match I lubed the upper cable. That helped a bunch on the wavering and the surging, but didn't cure it.

So I'm thinking I'll have to pull the upper cable's outer sheath and replace it. And I'm not sure how hard that will be with the grommet stuffed full of wiring. And if I'm going to run the wires through a different penetration point now is the time since there's nothing connected to the other end and I can pull them back out.

What I haven't done is to change the speed control's transducer. Could it be dragging, causing the wavering and surging?

Man, you got a lot to do to that truck....

[ArdWrknTrk]

Bob - I'm looking at Circuit 14, the brown wire shown below. It doesn't dim, but is just on/off.

I don't know if dimming the dash will cause the fog relay not to trigger.

Not sure what the pull in is for a relay, but ~7V stator power works too.

I never turn them down that much anyhow.

The diagram doesn't make me think so.

It looks like the same wire as the parking lamps

[kramttocs]

Bob - I'm looking at Circuit 14, the brown wire shown below. It doesn't dim, but is just on/off.

Adding a link here just in case we have something new to add to this Resources thread: http://forum.garysgaragemahal.com/Factory-wiring-locations-for-adding-additional-circuits-tp69894.html

(it already has C125 but we could add Fog lights as another good use case)

I was looking at other options after I posted the questions last night and if one has the Trailer package but no marker lamps, C915 is another good one. It is in the engine bay though.

For the firewall penetration, the part I cleaned off the desk was a gutted EFI grommet. The one that goes to the right of the gas pedal. It's what I used in the 86 (jampacked at this point) and I'd grabbed a spare from the jy. On the engine side I put a wire clamp on one of the gas pedal bolts to keep the wires away from the valve cover. Can take photos if needed.

I don't recall how you are implementing your future EFI change but that hole may not be free in your case?

Either way, if you need the grommet as well as if you need a clock pigtail to mate with C125, let me know.

[Gary Lewis]

Man, you got a lot to do to that truck....

John - When I think about what I have to do I get discouraged. But then someone asks me for a story about the truck and I go back over what I have done and I realize there's a whole lot more behind me than in front of me.

And, speaking of that, I'll lay out some of my thinking for y'all in order to get some feedback. Here's what I have planned for the next few weeks:

• Mission Control: I'll wire up the switches and add the wires I need for the fog and backup lamps.

  But I'll need relays to complete that effort and where to put the relays is a question.

• Aux Power: I'll finish the power box wiring and run the #2 wiring for power to the inverter. But I need to add a fuse in the circuit from the aux battery to the aux power relay, and where to place the fuse is a question.

• Air Compressor: With the inverter installed it is time to install the compressor itself in the tool box and the tank under the bed.

Let's say that gets done in the next month. That puts it at mid-January and I'll have ~5 months to the time to go to Ouray. Is that enough time to install the EFI and get it tuned? Sure would be nice to have it on that trip. But, I do not want to jeopardize the trip, so probably should save that for next fall.

In any event, there is going to be a space crunch when I go to EFI as the air cleaner box and another PDB go on the driver's fender. So back to the questions of where to put the relays for the lighting - in the PDB? And where to put the 150 amp megafuse for the aux power - somewhere that won't be in the way for the EFI swap.

In fact, I worry that the current layout of coolant recovery/windshield washer tank with the Cole Hersee smart isolator tucked between it and the fender will have to change when I go EFI. And I think I may better take some time to think through that issue before adding a relay box for the lighting and making new aux power cables.

Toward that end, I kept the driver's fender off of Huck. So I can bolt the air cleaner box and PDB to it and get a good idea of what space I have left.

Thoughts? Suggestions? Better ideas?

[ArdWrknTrk]

Jim - Getting the "lights-on" signal from that area an excellent idea! But, that got me to thinking about it and it turns out the same signal goes to the clock, and its wiring is poking into the Mission Control area.

Scott - I think that answers the first question. But that brings me to the second, and much more difficult, question of firewall penetration. And the simple answer is no. So if you have something that would create an option, please let me know.

That is a much more difficult question because I think I've stuffed the grommet for the speedometer cable with several wires that are headed to Mission Control, which packed it pretty tight. And now I believe I'm going to have to change the speedo cable.

The speed control surges. I realized the speedometer reading was wavering, and lubed the lower cable since it was easy, and that helped a little bit. That cable is one that I replaced as the truck went back together, and I remember the speedo wavering well before I pulled it apart, so that cable isn't the culprit.

When I had the instrument cluster out the other day as I was tapping into the fuel gauge wiring for the Meter Match I lubed the upper cable. That helped a bunch on the wavering and the surging, but didn't cure it.

So I'm thinking I'll have to pull the upper cable's outer sheath and replace it. And I'm not sure how hard that will be with the grommet stuffed full of wiring. And if I'm going to run the wires through a different penetration point now is the time since there's nothing connected to the other end and I can pull them back out.

What I haven't done is to change the speed control's transducer. Could it be dragging, causing the wavering and surging?

I'd love an update on the metermatch when you get it settled.

I am going to have to put it on my Christmas list.

[Gary Lewis]

Adding a link here just in case we have something new to add to this Resources thread: http://forum.garysgaragemahal.com/Factory-wiring-locations-for-adding-additional-circuits-tp69894.html

(it already has C125 but we could add Fog lights as another good use case)

I was looking at other options after I posted the questions last night and if one has the Trailer package but no marker lamps, C915 is another good one. It is in the engine bay though.

For the firewall penetration, the part I cleaned off the desk was a gutted EFI grommet. The one that goes to the right of the gas pedal. It's what I used in the 86 (jampacked at this point) and I'd grabbed a spare from the jy. On the engine side I put a wire clamp on one of the gas pedal bolts to keep the wires away from the valve cover. Can take photos if needed.

I don't recall how you are implementing your future EFI change but that hole may not be free in your case?

Either way, if you need the grommet as well as if you need a clock pigtail to mate with C125, let me know.

Scott - That's a good resource you have going there.

On the grommet and clock pigtail, I know I could use the pigtail but won't know about the grommet until I replace the speed control's transducer and see if that fixes the speedo/speed control problems. If so I'll leave the wiring that's in the grommet in place and try to sneak two more in - fog and backup lights.

So if you don't mind sending those things I'd certainly appreciate it. We'll talk price in the background. Thanks!

[Gary Lewis]

I'd love an update on the metermatch when you get it settled.

I am going to have to put it on my Christmas list.

Jim - I really like the Meter Match. Today I need to calibrate the Empty reading against the rear tank, which is empty, and then I'm essentially done.

However, there is a mid-point reading that can be used to try to make the readout more accurate, and over time I may want to play with that. That's because the gauge moves pretty rapidly through the middle and then slows down at the Empty end. So if I were to stop when I think I've used 1/2 of the tank I could push the button to train it to show 1/2 and it will interpolate above and below that to increase the accuracy.

If I calibrated the Empty setting and then took the truck to the station I could put 9 1/2 gallons in the 19 gallon rear tank and then make it read 1/2. Then fill it up and calibrate Full.