electrical demons

(2007 2500 4x4 Mega Cab 5.9 L)

I am having a weird situation here and wanted some advice on what you thought it could be. I will include everything I can think of that has occurred over the last three weeks. Any help would be appreciated.


switched out stereos.
This involved removing the alpine stereo installed and splicing the harness to my sony stereo. Each wire matched up nicely by color. The few remaining wires I didnt need were wrapped up and secured.

A couple days later, my alternator apparently quits working because my battery voltage was very low while driving. Took truck to oreillys to confirm alternator was out. They said it was. I drove truck to my mechanic's shop (1.5 hours away) and nearly ran the batteries dead driving it there. I had the alternator replaced.

A few days after not having any problems, there was a clicking noise when I started it the morning with a check engine light that came on. I took it to dealership and they said the primary battery needed to be replaced. I also had the dealership program an additional fob key for the truck while i was there. I took truck to Oreilly's and both batteries tested out fine. So I figured I would drive with them and see what happens.

Two days later without any problems, i get into my truck to drive home from my parents house. I turn the key and nothing. No clicking...no engine turning over..nothing. You could hear a pin drop. Interior lights worked...sterreo worked...just no juice. I switch out batteries with another 5.9 cummins my dad has with good batteries. No difference. Both batteries read 12.7 volts. So didnt seem to be battery issue. I cussed and took another truck back to my house. The next morning, I had my dad go out to truck and try starting it. It started right up without any problem. No hesitation...nothing.

What would cause this to happen? I have read some about the TIPM, but it sounds like the TIPM either works or fails...not hit or miss every other hour. Why would it not start....and then start...without anything being different except switching batteries that both being good supposedly. I am gun shy now about depending on my truck to start without any warning of this happening. Help!

An updated. I cleaned the battery terminals last night and looked for any loose connections in the wiring. Didnt see anything out of place. I also called the dealership this afternoon and spoke to them about it. They dont think it is the TIPM since it wasnt a total fail and started the next day. They still believe that their diagnostic report that indicating the battery was bad is correct. Which is possible. They asked if Oreilly's disconnected the battery when they tested... which they didnt. Oreilly tested them while connected to the terminals. Dealer said that testing them connected can give a false reading since its voltage current runs through both batteries. I am no mechanic, but I have tested batteries on other cummins before and each seemed to have a different voltage unto itself. But who knows. I plan on taking it by dealership during lunch tomorrow and see if their computer finds out anything. The search continues.

But I am not liking crossing my finers each time I crank her up. So far so good.

Good luck.. Electrical can be a *****.

I don't understand how it would be a battery if it mysteriously charged itself overnight and started fine the next day. That, and the fact that you swapped them out from a known good truck and it still didn't start, and that all the electronics were working when it wouldn't start makes me believe it is something else.

Wish u luck

Have you checked your ground and pos cables? sounds like one of them is bad or corroded at the other end.