I have a 1985 F 700 thats not charging. Alternator is good, does the ignition control module have anything to do with charging ?

 

I don't know the specifics of this truck but generally no. The alternator is a simple process and it basically needs 2 things to properly operate. It needs a +12V source to excite the coils in the alternator and a voltage regulator. Some alternators the voltage regulator is built in and some are a separate box. I assume you had the alternator tested at the store? I would check the wiring and check for a separate regulator.

Why do you say that it is not charging? Is your battery good?

 

Thanks, it has a new battery and altenator, it runs good until its killed the battery then it dies. Its on a cabover and I hav'nt been able to find the regulator yet. Thanks again.

 

New battery and new alternator does not always mean that they are "good". I have purchased a few new defective batteries in the past when I bought cheapo batteries. For this reason, I will never purchase another bargain battery from a discount store.

It might be worth it to remove the battery and alternator and have both of them tested. Can get them tested for free at a auto parts store.

If it runs good until you shut it off then it wont restart, I would be inclined to say that you have a battery issue or a drain on the battery. The other possibility but less likely is that your battery is awesome and will run your truck until it is shut down then not have enough juice because the alternator is not working. It could also be that you don't have the wires properly hooked up to the alternator and it is never energized to start the charging process.

I know this maybe taboo on this site but on all my older small ford trucks, I have always swapped to a GM style alternator for the following reasons. Internal voltage regulator eliminates many wiring/charging issues and they are cheaper than the ford alternator with internal voltage regulator. Only requires building new spacer and drilling out the pivot hole to larger diameter for the ford.

What brand and size of battery did you buy? Do you have dual batteries hooked up? Are they connected directly together?

I once had an issue with dual batteries and one battery was weak and the good battery continuously tried to maintain the charge on the weak battery and when I would let the truck sit for more than a day, it would not start due both batteries being discharged.