This is my second PCM And i think that it has burnt out regulator again.
I was told I might have an open or short in the harness.
The problem is that my battery is not charging and the windings in alternator ar not either. My mechanic said the problem is the connection to the alternator the white/black stripe wire. Can this narrow the short down with this info, or does anyone have any ideas? I am pulling my hair out at this point.

 

Does this have anything to do with this thread HERE because that doesnt sound like you have a bad PCM or regulator. That sounds like the radio or something else is just pulling the battery down over night. You said yourself the battery will get charged by the alt and PCM when the truck is running. Thats not a PCM/regulator issue. Unless you have something going on you arent mentioning

 

Measure the battery with the engine turned off. Fully charged battery should read around 12.4 to 12.8 vdc. Start the engine and it should read something more than what it read with the engine off. Something like 13.4 to 14 vdc. As the battery charges the voltage will decrease. Controlling factors are electrical load, temperature and battery charge. There is a temperature sensor under the battery, colder temperature will increase charge, higher temperature decreases charge. PCM regulates the alternater's output by varying the field voltage. Good luck...

 

The PCM/Alternator wont charge the Battery. I jumped the white/dark blue wire from alternator connector to a unused fuse port at fuse box with a 20 amp fuse now battery goes to H side on dash and check gage light and air bag ect. lights come on.

 

Red truck Thanks for your help. Not really sure what you are suggesting I should try after testing the battery. Depending on the out come of the test. Sounds like you have a lot of knowledge about this just need it in other terms.

 

I would check for AC voltage (bad diods in the Alt) as that will cause all sorts of problems. Just take a DVOM and put it to AC and with the truck running and the Alt charging check from the Alt + stud and ground you should not see anything above 0.01 Volts AC.

EDIT:
Just read your other posts. And this is your second PCM and you also have a new (or remand) Alt and battery. You also said that you traced the wire. I would start looking the all the Grounds for the PCM.

 

What I am thinking, it is hard to believe you have had two PCM failures and by understanding a little about how it works perhaps you can find a problem with the temp sensor or the field wiring voltage. I don't have my truck with me, but maybe the regulating field voltage can be confirmed to be within the correct range, as this is really what is controlling the alternator's output. As mentioned a ground or broken wire is most likely the problem. Good luck.

 

The ram is Fixed it was a short in the emissions wire. It says LDP wire repaired on my service bill. Thought I would let everyone know. And thatks for all the help.

 

Cool beans. I was just gonna reccomend to check for voltage drops too..lol

Thanks for updating

 

Brother, I don't understand the relationship between the LPD and charging system. The only connection is the PCM and then they are seperate functions. Can anyone explain?