04' F-350. 6.0 Diesel

236,000 Miles. I have gone through several alternators. At one point my only Option because I was hauling Horses was a Pep Boy alternator that I went through three in a Month.

The Last Pep Boy Alternator lasted a good +1 Year. before it went and I luckily found a shop on a Saturday while hauling horses to replace it with a better quality alternator and I chalked up the Pep Boys Lifetime warranty to a Loss.

That one lasted approx 2 years and went this April. Or so I think it went.
Same situation, Brother was driving truck with horses an hour away so I Bought an alternator, went to his location and replaced the alternator and then just turned the old one in without testing it for core. The funny thing is that this time the battery light started to instead of like the other times stay on it was flickering. When I got to the location and started it I didn't get any flicker or stay on but I still changed it out. (Can't strand the horses.)After I changed it the flickering battery light stopped doing it.

Come to the beginning of last week four months later and I am getting the battery light flickering again. I actually tried pulling and resetting the connector into the alternator and this worked for a week. Then one day driving vehicle just short of died on me. All the accessories shut down and everything but no battery warning light. So Under warranty and back to a very reputable place I took the Alternator back. They said it tested good. I put it back on and still problems. I had also bough a replacement connector but I never put it on.

So now I get my diesel Mechanic involved we tried to replace the PDM. and other troubleshooting including see if we were getting voltage from the connector which we were but did not have any troubleshooting info and it was just to make sure that the connector was good. We then put a POS alternator that he had in shop and after we literally shook the dust/rust out of it and put it on the system was charging.

So I took it to the alternator shop. They said that they got it working and replaced the Connector for me. that was two days ago.

Today the Battery light over bumps starts to flicker. I put it on my Schumacher Charger/testor that showed 9.8 Volts, 10% charge and 0% Alternator charging.

So I went through and did a clean up on all the terminals on both batteries where all the cables connect at the posts.

I then did some troubleshooting using a couple of posts from here.

First using a fused link I connected the Light green/Red on the altgernator to ground and with KOEO I got a steady Battery warning light.

Then using this Post and dchaimberlains Diagram I started troubleshooting:
https://www.ford-trucks.com/forums/1...ator-fuse.html

The first was the I Circuit the light Green/red wire.

I tested with voltmeter connected to ground and also connected to the plug prong in the alternator.

Readings were
KO 0 Volts which is right.
KOEO was 12.x volts which is wrong according to chart?
KOEO was same 12.x volts which is wrong according to chart?

A Circuit was a steady 12.x volts on all positions as well as Generator B circuit.

So what is Going on with the I circuit?

Does that connector and the two wires play a role in making the alternator work properly manage the voltage regulator on the alternator or are they just outputs of which I know lg/rd is output for the battery light?

AND to throw something else into the mix.

When testing right now and starting and stopping truck and sometimes having the Schumacher attached and sometimes not attached I had it on alternator test and showing 0 which is alternator not charging. The battery light was not coming on. Also between actual troubleshooting and while I was info gathering I had the charger charging the batteries.

In order to get to the alternator shop today before close I sent my brother with the truck with both batteries now at about 65% charge. I started the truck and moved it to park the trailer and NOW the Battery light is staying steady on.

Any thoughts on this?

I am waiting to see what the alternator shop says obviously.

But we know it isn't charging.
The Battery light only just started to do the flicker thing which on all the other alternators I had a solid Battery Light warning.

I did super clean all connections at the battery and the posts with a Dremel. Did this finally at least clear up my flicker problem?

I am perplexed by the I circuit readings. Are the high voltages damaging the alternators circuit?

I am at wait and see from Alternator shop but any input would be appreciated.

UPDATE: On way to shop brother hit a bump and light started to flicker and was off by time he got there. By his description, they put a voltage testor on alternator and got 13+ volts so it is charging?????

I really need help, I am confused, dejected and exhausted on this one?

 

Did you get any resolve to this problem? That is waaayyy too many alternators. I fear that I am embarking on a similar mission, different Ford HD chassis but certainly a charging problem. Thank you, Shawn