New to the forum, but avid reader. I have a charging problem with my 1995 F150 5.0 (N). Here is the situation I hope someone can help. Alternator not charging or putting out anything other than current state batterey voltage (12.4) no load. So I have hot battery voltage at YL/WT wire. good continuity of the WT/ BK stator jumper at the alternator connector. The LTGN/RD wire to the warning light (no voltage). I have run down all of the wiring, New battery and alternator still no charge. I found a connector for the LTGN wire hanging behind the battery disconnected but can't find the other side of the connector. I noticed that the charging warning indicator on the dash does not come on with key on engine off. Will this cause the alternator to not charge? Grounds are good all readings are taken off of the output post on the alternator which confirm the alternator is not pushing voltage. Please throw your thoughts into the mix. Alternators are pretty simple put 12v to the field and you should get max amps out right. This is my first F150 and this problem is killing me. I read that the warning indicator is looking for a ground from the alternator connector when the key is on and the alternator is not pushing DC volts out is this true?

 

I have hot battery voltage at YL/WT wire

To the harness connector but are you sure the Alt's getting it after that point?

That harness connector on the alt, it can suddenly turn problematic IE melt/deform, one or more pins not making solid connection to the alt.

 

It will not charge with no voltage on the LTGN/RD wire from the warning light.
Did you replace the dash cluster with one out of a 1992 or 1995 truck?
The LTGN/RD wire from the warning light is what tells it to charge, that is the control wire.



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So If I put 12v to the GR/R wire I should see the alternator come to life. I dont care if the dash light works for now. I will sort that out later. I used aligator clip wires to bypass the connector the only one I didn't do was the green because I thought that was output voltage and not needed to excite a charge.

 

Yes with 12v on it you may see it come to life.

 

I found the other side of the missing connector for the LTGN wire. The P/O had hooked it up to another connector. I connected it up and the alternator came to life. Thank for telling me I needed 12V on that wire. Big help. On to the next issue.