On our 2002 dodge 2500 5.9 gas the voltage regulator bit the dust. Unfortunatly dodge decided to make the VR part of the PCM so that if the voltage regulator goes out you have to replace the entire PCM in order to fix the problem. I have found a couple forums on the internet that explain how to wire an external voltage regulator and bypass the VR in the PCM. I have wired it all up and thetruck is still not charging. Here is a link to the directions that I used. Can someone take a look at this and see if they can explain it any better to me.

External Voltage Regulator Install - TheDieselGarage.com

external voltage regulator on cummins?? - Dodge Diesel - Diesel Truck Resource Forums


What I did was run 2 wires from the alternator to the VR. One of the wires I attached to the positive post on the alternator, the other wire I attached to the only other post on the back of the alternator. The post that I put the second wire on did not have anything going to it originally.

I ran those two wires to the VR and then ran a switched power to the VR top post. So the VR top post had 2 wires going to it and the side post had 1 wire going to is.

Any help is greatly appreciated!! Pictures would be awesome as well.

Thanks

 

If the PCM contols the alt out put there should be a field terminal on the alternator with a wire attached to it.If the small terminal you found had no wire hooked to it that is not where the PCM/regulator contol wire goes
Are you sure the Alt is good?
The field could also be Bat neg to energise

 

yes we have had the alternator checked. On the top of the alternator there is a wiring harness with 2 small wires that plug into the alternator. Do I use those two wires? Am I correct in attaching one of the wires from the regulator to the large post is on the alternator where the positive wire was originally?

 

I found this artical but is for an older mopar not sure it will help
I'm not familiar with the later alternators

Our alternators have two field studs on them, and are insulated therefor polarity doesn't matter. Just unhook the two small terminals on the back and leave the power and ground. ANY regulator will work. If it has only one field wire, find out if it is an "A" circuit or "B" circuit field, another words, does it provide positive or negative field? Whichever the case may be, hook it to one stud on the back of the alternator, and either ground, or hook to positive, the other stud. If your regulator provides both field wires, just hook them up...polarity don't matter. Presto, you're charging.

An alternator shop could tell you which of the wires do what