My 85 F150 is not charging the battery. I had the same problem last year and a wire from my EXTERNAL voltafe regulator had come off. I hooked it back up and all has been fine since. Now, I have the same problem again. I checked the wires and they are fine.

If the voltage regulator is shot is it possible my truck won't charge or no? I have 11.76 volts when running but 12.23 volts when the truck is off.

If the voltage regulator is the problem then I got one I can swap. If that is not the problem I also have another alternator I can swap. I just know the voltage regulator is easier.

Ideas?

-Matt

 

It certainly could be the regulator. You can try it first. If you have a meter, you can check the voltage on the "f" terminal with the truck running. Depending on how drained the battery is, will depend on your reading, but you should have something there. No voltage on the field means the alt will not charge. The regulator is what varies the voltage on the field.

 

Ok, I will check it out today hopefully. Maybe tomorrow. Thanks again.

-Matt

 

The Ford external voltage regulators have had some problems with the wires coming SLIGHTLY loose where they go into the connector at the regulator. You can try GENTLY pushing them up toward the connector and possibly restore continuity to the circuits.

I know that may hardly sound plausible, but I have seen that happen in four different Fords in this area alone. If the connector and the wires are badly loosened or distorted or won't stay tightened, you can get a new external regulator connector and harness from Echlin and splice it into the existing Ford harness.

Too, make sure one of the wires has not abraded against some metal and worn away the insulation. If you use the truck in some hard conditions, abrasion can be a problem.

I hope this helps to some degree!

 

Well, I went and did some searching around my truck. I swapped out the voltage regulator with 2 different used ones: NO CHANGE!
Looked at the wiring. I found 1 main alternator wire that was soooooo corroded I was surprised it still worked. Cut the bad part off and fixed it all up. Started the truck: NO CHANGE!
I found a main connector and noticed there was some green corrosion around it. Opened it up and it fell apart in my hands! Cut the connector out and hooked the wires together directly. Started up the truck: NO CHANGE!

Now I was getting frustrated! I had a spare alternator lying around that I knew worked. Swapped it out just for fun. Started up the truck: FIXED!

So it was the alternator. Cost to fix my truck: NOTHING! Thanks a lot guys.

-Matt

P.S. Loan Ranger: Checking that plug was the first thing I did. I had that problem before. Good call though!

 

I really am glad you got it found and fixed!! Fixed for free is even better!!