I was driving 2000 Ram with the Cummins Diesel down the road when the Check Gauges Light came on the dash. When I looked my voltage was at 18 volts. I shut the truck off and waited for a few minutes. When I restarted the truck it seemed to be ok. I few minutes later it did it again. I was wondering if the voltage regulator is in the Altenator or is it in the PCM?

 

It is in the pcm.

 

Thanks,

I was afraid of that!