Hello... Nub here. I have 1996 2500 with a 5.9 liter under the hood. Having issue of alternator not charging. removed battery and alternator, took them in and had tested. Battery was bad so replaced it, alternator tested out good. Re-installed alternator but truck is still not charging. GEN light comes on with an annoying buzzing and voltage gauge goes down, then truck dies after a short while with battery drained.

Air conditioning Compressor has been removed a while back with a by-pass pulley installed and a new key tumbler part of the ignition was installed about a year ago....

I am at a loss of where to look to see if there is a parasitic drain or broken connection. Any advice would be greatly appreciated..... Thank you!!

 

Welcome to DF.

Unfortunately, the voltage regulator is part of the PCM...... You can install an external regulator..... and maybe even keep the PCM happy. I think there is a DIY somewhere out there on the web.

You can grab the 96 service manual from the Service Manual thread in the faq section here. I do believe they have some troubleshooting steps for the charging system in there.

 

Thank you, I did download the manual. I did remove the alternator again, had it tested again (test good 4 different places) and reinstalled it after charging battery completely and cleaning all connection points. SO far no issue. Volt meter holding, no GEN light and temp gauge is working as well.... I don'r know what would be the cause. I will check it again in a day or so and should know if the alternator is working or still running off battery....

What in the ignition/starting curcuit could cause something like this? I ask because I will go to turn the key and get nothing but 1 click, turn it back then try again and it will start right up. sometimes the volt meter will not register and other times it will act just as it should.... Starter? Ignition relay?

 

Maybe a questionable ground somewhere..... which you may have already fixed. (inadvertently.)

 

check the battery cables there will be a separate cable coming off of batt. terminal going to fuse box check that connection if you still have trouble with charging let me know if your handy with a soldering iron I could walk you through replacing the driver inside ecm that controls alternator I can also supply you with a new driver for free they only cost me a couple bucks this is what I do for a living so I see these drivers fail very often.

 

Did you get it figured out?

 

Unfortunately no, the issue resumed after I let the truck sit for a few hours and went to drive it around a bit last evening. I double checked battery terminal connections and the wire connection of them both. I have not traced wiring from or to the starter as of yet, but think I need too.

The starting/not starting issues is weird as it acts like the starter may be going but yet when it catches, will start right off with no issues. I have a new starter to replace it, just haven't. That is why I asked about the starter being a part of the recharging circuit. Still unsure if I should replace starter.

Carcomputers.org - I am good with a soldering iron, I just do not have one but probably can get one to borrow. Thank you for your offer to help.

 

Wait, what? You can get repair parts for voltage regulators INSIDE the PCM?

 

My thoughts exactly lol

 

New Starter in.... Will see through the day if that is the issue. seems that the volt meter will show the alternator is charging 4 out of 7 turns of the keys.... keeping fingers crossed