Hey everyone, first post here. I tried looking to see if anyone had a similar problem to what I was having and couldn't find a result. So here we go: I've recently gotten my hands on a 1984 F-150 4x4 inline 6 cid manual 4 speed transmission with the rear re-enforced to make it close to F-250 weight spec.

When I got the truck I had a few problems getting it running, which it now does nearly flawlessly. However one of the problems that I inherited from the previous owner was a battery drain. If I hooked up the battery I heard a pretty resounding "clunk" from the starter, but it wouldn't kick over, it just loaded to get ready. This as it turns out was the source of my voltage drain.

Well after a bit of head scratching earlier today I did what every computer tech would do. I worked on isolating the problem from the rest of the system. I started by unhooking the battery then removing two wires from the starter relay. Both brown, one went into a fusible link and then turned yellow/red or yellow/white on the far end (was hard to get a good look). I traced this one back into the cabin and believe it to be the link to the ammeter. The other I didn't work on tracing as I had come to the conclusion that the ammeter was the culprit.

Having removed both wires I hooked the battery back up and attempted to start the engine. Result? Nada. No turn over. Hop out, unhook the battery, hook up the yellow/red wire, hook the battery back in place. Attempt to crank and nada again. So lather rinse repeat, only this time I hook in the other brown wire (the one I didn't trace). Go back to the cab, and she cranks. Ran a quick drain test (both circuit and DMM) on the battery, and lo and behold no drain.

So I'm left at this point believing that I have this yellow wire, which as far as I can tell is the ammeter wire, hanging out in my engine compartment. I'd really like to know where it goes to, and (more specifically) what it should be hooked to. The Haynes manual and the Clymer manual both seem to indicate that this is the ammeter wire, but neither of them specifies where it should hook into. Can anyone give me an idea?

 

your amp gauge should have a shunt in it,so no large high amp wires have to enter the cab.pm franklin2 he is our electrical mod and knows alot about this stuff.

 

If it's yellow/white dot wire, it should go to the A+ terminal of the regulator. Should tie in to the orange fuse link going to the + side of the starter relay (if it's yellow/white dot).

 

Your charge indcator wire at the regulator should be green/red stripe

 

Let's not confuse the issue here. There are TWO different ways these trucks are wired from the factory. One with altenator and oil pressure idiot lamps and one with ammeter and oil pressure gauges.

Here is the factory diagram. Do note the factory diagram shows how BOTH systems are wired, so part of the diagram will not apply to him. It is clearly marked (WITH GAUGES) at the relevent parts.

Power Distribution: 1984-1986

http://i447.photobucket.com/albums/q...scan0002-4.jpg

Charge Start and Run:
http://i447.photobucket.com/albums/q...scan0002-2.jpg

 

So delete green/red stripe with ammeter. Not used

 

It is used, however it's wired differently, and not used as a charge indicator wire for trucks with gauges.

Instead of the Green/Red stripe wire being hooked to the "I" (Indicator) terminal of the voltage regulator (For idiot lights), it's instead hooked to the "S" (Stator) terminal of the voltage regulator (For Gauges). Then the green/Red stripe wire goes directly to the ignition switch (Hot in Run (Gauges). Instead of the altenator indicator lamp.(Idiot lamps)

 

Thanks for the clarification 81 F50 explorer........I just checked my factory service man and it does say not used with ammeter and doesn't specify anything else other than that. Good to know, thanks for covering my 6!

 

Thanks for the help with this folks. Still investigating, I went out with a flash light after work to investigate (don't get off work until after sundown). The side of the fusible link that was hooked into the relay looks brown, after cleaning it a little it looked like it could be red, or reddish brown. The part of the wire on the far side of the link from the relay was straight yellow, pretty decent gauge too.

|Relay| -- Brown or Red Wire -- |Fusible link| --- Yellow wire ---> cab

I'm going to PM franklin2 about it and see if he can make heads or tails of it since those wiring diagrams show me 3 potential things it could be. Right now I'm thinking it could be for the trailer lights, but I'm not positive since I don't know where the junction block is.

I'll keep everyone posted.

 

The junction block is located on the passenger fender skirt in the area of the starter solenoid if your truck is equipped. However the Trailer Battery feed leads to the back bumper down the frame rail, not into the cab.

The only problem with the factory wiring diagrams is it shows every option the truck could come with, not nessecerily what your truck has on it.

Circut #37 Yellow wire (no tracer): Battery Power feed.

This circut powers a number of things, including the ignition switch, and the fuse panel in the cab depending on where the circut ties in.

How many fuse links are coming off the starter solenoid and what are their seperate colors if you have more than one. I could narrow it down that way.

The major (essential) circuts coming off the starter solenoid...

1) Circut #301 Red Fuse Link: Connects to #37 Yellow: Powers EEC Relay and Processor. (EEC IV computer controlled engines Only) (Not used with DS-II)

2) Circut #302 Dark Brown (or blue) Fuse Link: Connects to a Different #37 Yellow wire: Fuel Pump Relay (EFI or "hot fuel handling" only)

The following refers to ammeter and oil pressure gauge equipped trucks only.

3) Circut #291 Black Fuse Link: Connects to #38 Black/Orange Stripe wire at Splice #219. Then continues to splice #201, which connects to #655 Red/Orange Ammeter wire and #36 Yellow/White Altenator Regulator wire together. #38 black orange continues as a shunt wire from splice #201 to splice #202 where yet another #37 yellow and #654 Yellow/Light Green (ammeter) wire connect. Circut #38 Black/orange continues from splice #202 as a regular wire, and goes to the battery terminal on the altenator.

4) #37 yellow wire continues from splice #202 mentioned in (3) above, and connects the two fuse links on top of the passenger fender skirt at splice #211. Dark Green and Orange fuse links. The Dark Green one connects to another seperate #38 Black/Orange wire at splice #212, that goes from there to power the Headlamp switch and the fuse panel. The Orange fuse link connects to yet another #37 yellow wire at splice #214 that continues on to power the ignition switch and Fuse F-13 which controls Brake and Emergency warning lamps (hazard).

 

Where are you at right now with this problem? Truck starts and runs fine, and everything works, except you have this extra wiring hanging there?

Don't worry about the ammeter wiring. It serves no function except to feed the ammeter, which usually never gives any useful info in the first place. It cannot drain the battery unless someone has messed with the wiring.

 

Exactly. It's not critical (beyond being a potential point of saftey), I'm just trying to figure out what exactly that wire should be hooked to.