I have a 1991 Dodge Ram with a Cummins Turbo Diesel in it that will not charge the battery. It has a new battery, new alternator (second one) and a new voltage regulator. I have power on both sides of the regulator. The alternator is grounded. The battery has new chassis and engine grounds. The voltage at the battery while running is 11.6 volts and drops when lights are turned on. The voltage at the back of the alternator reads the same as the battery. The alternator is physically cold to the touch indicating it is not working, but I took it back to the parts store along with the old one and they both tested good.

I have checked all the fuses and also the fuseable links along the left fender. The truck is not equipped with an ammeter, but it has a voltage gauge which reads the same as my meter. The 1991 Dodge does not have the PCM controlled charging system like the newer ones do.