Larry the Lariat - My 86 F150 4x4

Probably check that the pawl spring is pulling it into the quadrant teeth
Maybe it's broken or the pivot is rusty. Maybe the quadrant teeth are worn.

Hi.
Maybe a little oil here and there could fix it ?

Consider the cobwebs officially blown out!

Took Larry out for a 25 mile uneventfully trip. Of course, the whole trip was 27 miles, so the last two miles were adventurous. 😂

Adventure 1: going up a steep hill when suddenly I hear something drop and metal dragging. Immediately I think my driveshaft just came loose and coasted into a parking lot we were right at. Died laughing when I realized it was the spare tire carrier. 😆 Apparently I didn't spin that eye bolt properly and it must have shaken loose and dropped.

Started it up and the battery was REALLY WEAK... Took a bit to fire up and I figured I may be limping it home. Had to sit through a red light and then up another steep hill. Did fine. Four way stop, no problem, and then...

Adventure 2: it just died on me. No where to pull off and a car behind me so I'm coasting at about 25 in a 35, trying to start it back up to no avail. Weak battery and it doesn't seem to be firing. Picked up some speed down a steep hill and remembered I was coming to Holland trail, a wide and not busy back road, but it's a SHARP right turn. No power steering or power brakes while I slowed from 45+ at the base of the hill and rolled off on the side street. Dead battery? Bad alternator? Oh, I was out of gas... Weak battery was the secondary issue. 🤦🏻‍♂️ Called a friend who gave me a jump, added the two gallons I thankfully had brought with me just in case, and finally got it fired up after pouring the remaining few drops into the carb that was bone dry apparently.

Got home ok. So I'm not sure if my battery is just weak or the alternator is bad, I'm leaning towards alternator since the battery should not have been down after a 25 mile drive.

I need to figure out why my gas gauge doesn't work. Sending unit was new with the tank a few months ago. Seems Larry has had a few electrical gremlins.

But the good news is... We took Larry for a 27 miles drive, including four miles on the interstate. Hit 70 on the ramp and easily passed 80 before slowing down. I let it slow to 60 when no one was around and then fed it the onions... That 351w comes alive pretty quick at higher speeds. Passing will NOT be an issue. 👍👍🙂 Or maybe I'm just giddy that I have a V8 since I'm used to a straight six. 😆

Screenshot was while we were waiting for a jump.

Two steps forward and one step back, but it sounds like a successful trip overall!  

Does Larry have a single tank?
Where was the gauge reading while out for a drive?
You can probe the resistance to ground from a connector without dropping the tank.
According to the EVTM the ground is up by the radio.

As for your battery do you have the 1G or 2G alternator?
Your '86 has an ammeter, correct?
If a 2G I'd strongly suggest getting rid of it.

Congratulations!  In spite of the defugalties you have a good outlook.

And, speaking of "feeding it the onions", as you peel this onion you are working your way toward a massive plate of Onion Rings!  

Single tank. Brand new, and a new sending unit with it, just a few months back. Gauge was on E, but it's always on E... I've had 10+ gallons in it and it never moved. If I'd been thinking, I'd have pulled into a gas station and filled it up, but I started the drive planning on going five miles so that never entered my mind.

Ammeter... Yeah, maybe I should be paying attention to that. I'm not used to having one as my 70 has idiot lights. 😂

Not sure on the alternator. I would presume it's whatever was stock. I'll have to look it over. I may pull it and have it tested.

Do you run a stock alternator or have you upgraded?

If you have a new sender and it was reading empty there's an open circuit (somewhere)
Best to test the ground side first and then look for pulsing 5V coming from the ICVR to the sender with the key on.

The troubleshooting section of the EVTM here on site can help you figure it out.

'86 was a year when your truck could come with a 1G (fender mounted regulator box) or a 2G (integrated regulator)
The 2G's had a power plug with two black orange wires that would corrode, melt and sometimes burn up.  🔥
The 1G has a power cable bolted to a lug on the back.

The ammeter was never any good anyhow, but the wiring is different, so I asked because tracing the fault has different steps.

Again the testing methodology is available in the '86 EVTM.

As always, thanks for the great info! I need to read up and go through that troubleshooting. May have to print out the EVTM and put it in a binder. I really need to just order a complete service manual for Larry. I'm just cheap so I haven't yet. 😜

You can buy an authorized reprint of your specific year EVTM.
https://www.themotorbookstore.com/1986-ford-f-series-truck-electrical-vacuum-troubleshooting-manual.html

I found a used '87 copy on eBay for $25 delivered...
It's been well worth it for all the help they offer.

chirkware wrote

Do you run a stock alternator or have you upgraded?

Sorry, I didn't catch this question.

After my 2G killed batteries a couple of times and then melted the wires I gave up on replacing it and went with a 130A 3G from a '92 Taurus 3.8l V6.
There's a few wiring changes involving an actual power cable and a Megafuse...
Since you have an ammeter you would need to disable it or have it converted to a voltmeter by Rocketman Innovations (~$50)

Gary has a writeup under 'Bullnose Upgrades' in the documentation.
https://www.garysgaragemahal.com/3g-conversion.html

Ok, so I took a quick look, and I don't see a voltage regulator where this diagram shows ones should be, so I'm assuming that means I have the dreaded 2g alternator?

"There's your problem lady!"

So your alternator has two plugs.
One grey regulator plug (ovalish) with green and yellow.wires.
And a chunkier rectangular plug with two black/orange and a white/black wire?

Test first (of course) but consider a 3G upgrade to eliminate dead batteries and the chance of fire.

When I look at the 86 EVTM it seems the stator wire does not connect to the regulator (the center pin is empty) and the stator only comes out in the rectangular charge wire plug.



This is a little different than my 87. Probably because I have a voltmeter and not an ammeter.

Of course the wires are caked in 37 years of grime, but here's what I can see:



I can't get where I can make out the colors of those wires at the bottom, other than the obvious BLACK.

I think this is the regulator built into this 2g alternator:



Best I can tell, that's E43F-10316-AA.

I'm out of daylight for the evening, so I'm gonna read up on testing three alternator. If it's bad, and I believe it will be, sounds like the 3g upgrade is probably the way to go. I'd probably be fine just disabling the ammeter. These things seem to work well enough for a voltage meter:



BTW: After 24 hours with the battery on a 2A "maintenance" charge, it reads 13.5v. I'll leave it unhooked and see how it holds it's charge just sitting a couple of days.

Yes. ASI is the regulator connection.
The black square with an arrow pointing at a screw "ground here to test" is the integral regulator.
See if you can get the lower charge plug free from the alternator housing.
Is there corrosion on the contacts? Is the plug itself melted?
These are the initial concerns outlined in Ford TSB 96214

Hopefully your battery wasn't toasted by a bad alternator.

Feel the back of the alternator to see if it's hot(ish)
This is a sure sign that the diodes inside have failed and are passing current.

If you have a multimeter, with the key out and the doors closed, set the leads and dial to amps, place it between the negative cable and the negative battery post.
There shouldn't be any draw above say 30ma, (radio and/or clock memory)

I think I'm just gonna go ahead and upgrade to a 3g alternator. I plan on keeping this truck a long time, so let's just eliminate a known problem area now.

I just submitted an offer on an new old stock Ford remanufactured (I guess it's ROS not NOS) 3g alternator that has one of the recommended part numbers from the conversion guide. Hopefully they accept my offer and I have an alternator for $50. 😃

I'll take some measurements to see what length wire I need.  Found this eBay listing where I can get 4awg our copper battery cables made to whatever length I want. I'll get a short piece plus a longer one, and put a 175a megafuse between.

I'll order this harness pigtail as well.

I think that gets most of the parts, but I need to go back and read through the guide again to see if I'm missing anything. I think I still need a 20a fuse on the smaller wire in the harness (I'm partly documenting my thought process here).

I know I need to decide what to do with the ammeter as well. Part of me says just disable it and run the little thing that plugs into a cigarette lighter.

Did you get the 95A (4 hole) or 130A (2 hole) 3G? That would influence the Megafuse you'd want.
The pigtail pair looks good if you have a crimper and some fittings.
I don't think you need to fuse LG/R the exciter wire.

You certainly don't 'need' an ammeter, or a voltmeter....
Unpinning the R/O and Y/G wires at connector (C610)will completely isolate it.

Many of these trucks only had an indicator to show charging.

Unlike Gary's instructions I'd want to know power in the cab like your USB would show.
It seems an expedient solution without opening the cluster.

Just to show that I'm reading the mail....

I want to know battery/alternator voltage, not after the drop through the wiring.  If you want that get a Sony radio like ours, Jim, and put it on voltage display.  

If you are getting the 95A alternator you might still be able to run the factory ammeter.  I'm pretty sure that the shunt is sized to allow 70 amps as there was a 70A alternator available and I can't see Ford not sizing the shunt for that.  I doubt the shunt would be hurt with the extra current but you might see the ammeter make some rapid swings.

As you know my truck came with a voltmeter in the cluster. I don't need to know how much makes it to my radio...   edit: I did cycle my radio display today and see 14.1V. So a .25V drop from the 14.35V set point of my 3G regulator 
State of charge will definitely show up in the cab.
Not everybody has a winch, 3,000/6,000W inverter, onboard air compressor, and a military radar station loaded in their truck.

The 95A 3G is a very viable upgrade for anyone with a 1 or 2G.  It puts out a lot more at low rpm's than either of the earlier units and seems more stable.
IMHO, more than enough for a stock pickup, but if you get into something like electric fans, heated 6-way electric seats, whatever, the bigger option is the better choice.

Edit: rapid swings would be a huge improvement over the stock setup where you don't see anything unless the alternator is cooked or you have a dead short.
I still don't know that the shunt (which is all that's feeding the cab) is sized for 95A+.
In principal it can't be, as that's how it functions. The ammeter failures I've read about come from the ammeter gauge windings turning into a toaster and melting right out the back of the instrument.
If you don't notice that, it burns through the harness and sets the dash on fire.

I was with you 'til we got to the radar station.  Perhaps that the front/rear cameras & GPS?  Or the Garmin GPS?  

Yes, I have a lot of electrical load available.  But that 130A 3G I got from you does the job.  So a 95A unit would be a nice upgrade for most people.