1g to 3g Alt Sawp on 1983 6.9 (Wiring Question)

[1983idi]

I am trying to do the 1g to 3g alternator swap on my 1983 6.9 F250. I have a few questions and I am probably just overthinking things but I want to do it right.


1st issue is that my old external voltage regulator only has 3 places with wires going into it. The white and black wire that ran from the old 1g alternator runs past the voltage regulator and goes to a relay on the passenger fender by the headlight and then a couple red wires run back from the relay and run into the main harness. What its this for? Do I need to worry about doing anything with this wiring? (See pictures in next post)

2nd question is about the green wire that gets ignition power and runs thru the ammeter on the dash. While stumbling around cyberspace trying to figure out my 1st question I came across a couple posts saying that the ammeter on the dash would not be able to handle the 3g alternator and would burn out? Has anyone had issues with this?

Thanks for any help!

 

[1983idi]

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[dancrowley]

Check out; Help on 3G page at http://www.garysgaragemahal.com/

 

[IDIBRONCO]

2nd question is about the green wire that gets ignition power and runs thru the ammeter on the dash. While stumbling around cyberspace trying to figure out my 1st question I came across a couple posts saying that the ammeter on the dash would not be able to handle the 3g alternator and would burn out? Has anyone had issues with this?

I can say that the factory ammeter in my 1985 handles a 3G alternator just fine. I just looked and if my truck has that relay, it's hidden because I can't see it.

 

[Laine D]

I can say that the factory ammeter in my 1985 handles a 3G alternator just fine. I just looked and if my truck has that relay, it's hidden because I can't see it.

That’s weird because my ammeter now longer works after my 3g swap. At first i thought I did something wrong. Everything is hooked up right

 

[1983idi]

Thanks for the link and for the answer to the ammeter question.

After a ton of searching I was able to answer the first question on my own. The 1983 glow pug system is a one-off system. The relay I am pointing to in the 2nd picture by the headlight is what's known as the "afterglow" relay. It got stuck on all the time and fried glow plugs so Ford put out a TSB to get rid of it and they also changed to the standard 6.9 glow plug system in 84 which is what most people are familiar with.

Once I knew it was just for the outdated glow plug system I continued with wiring my alternator the same as all the other wiring write-ups I had seen and I had no issues. I started it up and immediately got 14.38 volts at idle which is almost 2 volts higher than I've seen before. If it wasn't for the stupid afterglow controller I would have had this job done in an hour or so.

Hopefully this helps anyone else that has an 83. If you don't have a manual glow plug controller and are trying to do this you'll have to figure out how to re-wire that white & black stripe wire but since I've got a manual push button I didn't have to. I seriously doubt anyone with an 83 has a GP system that's not been updated and is still working tho.

 

[franklin2]

You should not have to worry about the ammeter in the dash, because you should be bypassing it. You should take the original orange/black output wire and tape it up and stick it back in the harness. It is too small to handle the output of the newer alternator. Guess what? The factory ammeter is hooked into the original output wire. So if you tape the original wire up and tuck it in the harness, your ammeter will not work and not be subject to the wiring overheating. You should run a new heavier output wire from the new alternator directly to the battery to handle the output of the new alternator. Most swap articles tell you to do this.

 

[1983idi]

On mine the original 10 gauge orange/blk wire that came off the 1g alternator split off into 3 different wires that ran back into the cab harness. I ended up connecting them to battery power because it looked different than most of the write ups. I have to trace them and find out where they all go but I did run a 0 gauge wire with a 175 amp fuse from the alternator output to the battery so hopefully that works for the time being.

 

[Scotty4]

Not sure how close to the same it is, but I just did my 85 and the three wires coming off are the: Yellow=supply for two fusible links going to ignition (orange), and lighting (dark green). There is another going to the glow plug harness, I believe and one more which I can't remember. The truck is at the shop or I would go look!

 

[franklin2]

Those are the important wires that power the whole truck. They need to be left hooked up. That's why it's easiest to leave all that original, and just tape the leg of the alternator off and tuck it in the harness. That whole thing is powered from a fusible link that is hooked to the large terminal on the solenoid. So that needs to be left as is.

 

[franklin2]

Here's the circuit for a 1986 diesel. You can see the whole thing is powered from fuse link J.

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