Hi All,

I've just joined this fantastic forum, but before I did I read all 134 pages of threads!!!!!. I'm hoping that someone may be able to help please. I have a 1998 Ram 3500 great west van with the 5.9, 4 speed auto with only 45000miles . The van is in superb condition but recently I've had a problem regarding low voltage. My obd 2 scan comes up with p1682. Initially I thought alternator and removed it and had it bench tested, all okay, battery is okay, I then fitted a replacement PCM from Florida. ( at great expense!!!!) but my problem still remains, which leads me to think that my original PCM was okay. Could someone advise please what I should do next, there are very few people over here that can work on American vehicles, but I really need her fixed. My voltage gauge sits about 11 volts but after short drive check gauge light comes on. Many thanks in advance.

Mack

 

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First get that battery on a proper battery charger. Letting them sit undercharged it a great way to kill them for good.

After removing cleaning and re attaching the main grounds, and adding one between frame and engine if one does not exist, Measure the battery voltage at the battery
then start the engine and test at the battery terminals, on the connectors, then the battery studs themselves.

Then measure at the larger terminals on the back of the alternator.

Take measurements at idle speed and at ~1500 rpm.

Post the results.

 

Hi,

Many thanks for the prompt replies, I will do as suggested and report next week on how it goes,

Mack