Charging issues 2008 Ram 1500

[Capt B]

I have a 2008 Ram 1500 5.7. I hadn’t used the truck in a couple weeks and started the truck up and it’s no issue. Drove the truck about 20 miles and shut the truck off. Restarted and drove another 2 miles and shut it off. Truck sat for about 15 minutes while we loaded it up. Started it up and drove about 500 ft when the truck suddenly died. Lilted the hood and found a fire under the hood on top of the alternator. Put out the fire and had it towed home. Wires going into the alternator were burnt off and I replaced them found a burnt fuse in the TIPM. Still no charge. Rewired to the old school external voltage regulator and have the truck running. Trying to find out where the signal comes from to trigger the alternator to charge though the onboard circuit. Does it come from the PCM or the TIPM?

 

[Capt B]

The fire was caused by a squirrel nest on top of the alternator

 

[jws123]

Did you have the alternator tested after the fire?

 

[Capt B]

Replaced alternator so issue isn’t there. It has been running well since I put the old school Chrysler regulator in. Just trying to rerun it to stick to put out the check gauges light on the dash

 

[Capt B]

I’m not getting a signal to turn on the alternator from the computer or tipm. Alternator is charging well through the Chrysler regulator. Also having issues with the power seat and headlights

 

[FabricGATOR]

The PCM now controls the alternator field in more modern vehicles.
Most times, the field has power and then the PCM modulates the ground to energize.

Like with fuel injectors and ignition coils, if the PCM receives a direct power 'spike' it can blow the circuit 'driver' within the PCM and would (could) be repaired.

BUT, before I would spend that money, I would verify the associated wiring by pinning it out from alternator, PCM plug, TIPM, etc

(trouble shoot before parts changing) (though, every once in a while, even a blind squirrel finds a nut)

Please return and let us know how it goes and how you eventually get her restored to normal (including cost in 2023 dollars)