Well I know the PCM controls the AC and charging system so I replaced the PCM and I am still not getting the alternator to charge. I had the alternator checked and it is fine. I checked the ASD and all my wires, no breaks and getting power to the fields.
Someone suggested regulating the alternator so I tried that but could not isolate the fields. It would charge but kept overcharging.

Anyone have anything else. Thanks

 

How did they check it? A shop or a shadetree? What values did they come up with on the test?

 

My Uncle, a mechanic for 40 years for himself and dealers knows his stuff tested it. The ol' man at the alternator shop suggested we bypass and put the regulator on it. And then we heard something about the throttle position sensor might be the issue.

Used the shop manual and tested all the fields, ASD, alternator with the voltage tester. Had the voltage tester in line when the truck was running juice was running to the harness to the alternator and through the relay, but not exciting the field in the alternator. The alternator must had both fields hot so we grounded one. Nothing we did worked.

When we tried to put a regulator to bypass with juice from the key side the truck started charging but overcharging well over 16 amps!

 

Did you test the alternator for AC voltage output? You should only, of course, see DC voltage leaving it. If AC is present rectifier bridge can be the issue. Just seems very odd to me that everything is checking ok...Hmmm

 

does the tach work if not the crank sensor failed pcm needs to see engine speed to control a/c an alt.control

 

did you solve this?Iam having simliar issue maybe relay on firewall driver side?