Not sure if this is the spot this should go and I tried looking this problem up on here but I cant find it.

I am having a battery charging problem on a 2006 f350 6.0 diesel. It's not the batteries, or alternator or the pigtail. It is the wire "green with red stripe" going to the alternator. Sometimes it has 12+ volts and other times its has 1.7 volts or .4 volts. Of course when it has 12v the alternator is charging and the rest of the time it is not. What controls the green with red stripe wire and where does it go? Does anyone have a schematic of the charging system?

This problem has been going on for a while and has killed one set of batteries and I have verified the alternator is good. The battery idiot light is on sometimes and sometimes it's not. I have read all the post on here that I could find but I did not find one that addressed this.

Thanks in advance

 

After digging and digging, I found this past thread https://www.ford-trucks.com/forums/9...or-no-ecm.html

It looks like by the diagram, the green with red stripe is a output from the alternator?

I have double verified that the pigtail is good, minus the holes I have put in the wire insulation, which would mean that it has to be the alternator!

There is no rhyme or reason to when this alternator works. Its on or off when its cold or hot, just started or ran for 5 hours. The battery idiot light doesn't seen to have any timing as well. Sometimes it is on when the alternator is charging and sometimes not.

Can anyone verify that the green/red wire is a output??
Thanks

 

were u able to find the problem with the charging system because I am having the same problem the battery light comes on and of at times and when charging the lt green wire has almost 12Volts but when not charging the wire has approx 1.5volts can't seem to find out whats going on I would appreciate a quick response thanx

 

Hey everyone. I signed up just to share what I have found. I have an 04 F250 6.0 6spd. The truck stopped charging. My radio has a voltage read-out so I was able to monitor constantly. Voltage wasn't constant and never above 12.9v. Had alt tested, bad, replaced. Still not charging. Tested wires at alt. I had a low signal to alt.

What I've learned so far is the computer tells the alt to turn on after glow plugs shut off. Glow plugs may stay on for up to two minutes after startup. So I replaced the glow plug module. Still not charging. Went and spoke to the Ford Diesel Tech at the dealer. He had no clue but he did pull up a wiring diagram that shows the oil temp sensor(2 wire) to the right of the oil filter signals the glow plug module to shut off the glow plugs.

I checked that sensor and found both wires corroded and stripped. I wiggled them and everything came back to life. So far I've repaired the harness, the voltage is consistent again but I think I fried my third alt. I did a lot of digging in a lot of forums as well as shops specializing in diesel and Powerstroke. For such a common problem, few were able to solve the problem without buying a bigger alt or increasing battery cable size. Check these wires.

Also my boss has an '05 6.0. He didn't have charging problems but the truck would fall flat randomly. His Powerstroke guru fixed the connector at the same oil temp sensor. The clip had broken off causing a loose connection. Which solved the problem.

Hope this helps.