Fuse was ok, we took it around to some dodge dealerships, everyone is of the same opinion, Either it's another bad alternator or a bad computer. All the wiring checks out. I returned the alternator again and this time ordered a new 136 amp alternator, (not remanufact), If this doesn't do it, I'll be computer hunting because that means mine is not telling the alternator to charge.

 

Look in the service manual(service manuals are available here somewhere), There is a section to test the output of the alternator not using the pcm. This will tell you if it's working or not. It's basically full fielding it to test output. Do this before you spend your money.

 

In case I do have to replace my ecm I started looking for the correct part number. I've heard that you have to program them to match the truck. The odd thing is, I have a 5.2L but the computer number is P56046 347AD. Everywhere I look the "347" refers to the 5.9L. All the computers that match my 5.2 is the 343AE number. I need a key to figure out which computer was meant to go with a 5.2L automatic 4 speed, 4x4 with AC.

 

Yep, on the 98 and up trucks, the PCM needs to be flashed to the correct VIN, otherwise, it whines...... (ABS and SRS don't wanna work.)

You should be able to order one thru your local autoparts store, and it *should* come already flashed to your vin. (which implies they will ask for it when ordering.....) If it doesn't, and competent shop should be able to deal with it for ya.

 

Here is a new twist, The "battery Temperature sensor" it can shut down the alternator if it thinks the battery is too hot by telling the computer to stop charging. Thoughts? comments? It seems cheaper and easier than a new computer, but how do I test it? Can it be by passed?

 

A scanner that can read data should tell you what the PCM thinks battery temp is. If it's wrong, well, that could very well be the problem.