1991 Dodge Ram Diesel issue

[Johnny Mullet]

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.

[walldogg03]

you mentioned that you changed all the chassis grounds. did you check your positive cables to and from the starter, you should also check your positive cables at the alternator, and make sure you enough tension on your alt belt. also another thing to look for is are you getting bat voltage to the alternator with the engine off because alternators need electricity to make electricity, check for a dead short by placing your dvm on dc put one lead on ground at the alt and the other to a part on the chassis, if you get voltage then you have a dead short somewhere, you can do the same at the battery to help find your short (if you have one)

[ram3500]

Give this a try.. Seen it happen before.

http://www.dieseltruckresource.com/d...battery+charge