Over charging

[DodgeFreak]

Our 92 Dodge D350 cab and chassis we bought off of a mayflower moving company and right off the bat we noticed an over charging issue, drove it home 10 hours and cooked the battery, It has had someone hack the wiring on it and it has an external voltage regulator, If you disconnect the voltage regulator it looks "according to the gauge" that its charging properly but then it drains the battery a couple days later. We tried a known good regulator and a new one and still over charged, tried a know good alt, (off of dads running cummins) and it still over charges, Looks like a couple of the fusible links were by passed which needs to be corrected. What else should we look for??

[Hansen01]

Make sure the plug that goes into the regulater is tight with very little movement, and the ground that goes from the core support to the ground on the battery

[poof]

Im having the same problem. i burn up battery's and regulators regularly. i have burnt out 5 already this year. I have tried everything i can think of. if anything comes out of this post it will help many people.

[cmann250]

Make sure the voltage regulator case itself is tight to the firewall. That's the way it grounds. I went as far as putting another screw in the hole that Dodge doesn't use.

DodgeFreak- do you have a pic of how the alternator is wired up? The wires going to the VR could be backwards

[DodgeFreak]

I don't have any pics yet, I'm thinking about bringing the truck up to my place this weekend if i get the afc housing leak fixed.(its 3 hours from me at my parents place) I'll have to dig into the wiring, i always like fixing other peoples wiring screw ups.....good point on the wires being backwards, Is there a wiring diagram floating around here for it?? I used to be able to get on shopkey5 from the college i went to but they went and changed the password on me lol.....

[cmann250]

IF the PO wired it like the factory would have, here's how it would be:

The top pole on the alternator goes to the VR, left terminal (right is unused)
The bottom pole on the alternator goes to the ignition switch
Then there's the ground for the alternator and the hot going to the battery, but they should be obvious.
On the VR, a wire should go to from the bottom terminal to the ignition switch

My description is assuming you are standing in front of the truck, facing the firewall with the VR screwed onto the firewall, and the alternator installed

[BobS]

Here's what I have. Ignore the gasser ignition information.

The harness plug:
[


It doesn't matter which FLD wire connects to which/either alternator FLD terminal. They both go to the alternator brush leads and connect to the rotor coil in the alternator. Also a loose ground between the negative terminal of the battery and any connecting points to the regulator will eventually kill the voltage regulator due to voltage spikes. Solid state devices [the voltage regulator] will fail whenever they receive continuous voltage spikes. Run a ground lead from the engine block to the voltage regulator mounting bolt. Grease the bolt and the wire terminal ends.

[DodgeFreak]

thanks the images didn't show up....

[BobS]

thanks the images didn't show up....

They should now be viewable...

[DodgeFreak]

quick question, if they wired the fld wires with a different color is there anyway to tell if its fld wires and not something else??? say i pull the plug from the volt reg, top plug should be 12v hot with key on??? and then bottom should be fld wire to alt and another fld wire to the top...

[BobS]

quick question, if they wired the fld wires with a different color is there anyway to tell if its fld wires and not something else??? say i pull the plug from the volt reg, top plug should be 12v hot with key on??? and then bottom should be fld wire to alt and another fld wire to the top...

Pull the plug from the voltage regulator. With the engine NOT RUNNING use a test light or a VOM to probe the ignition terminal of the plug with the other test lead grounded. With the key off it should read zero. With the key on it should read your battery voltage. BOTH voltage regulator wires should go to the alternator field leads, aka the rotor connection. Also NOTE: Neither of these two wire should go to ground when the plug is disconnected and when the ignition switch is in the off position. A faulty intermittent ignition switch contacts [or harness connection somewhere between the ignition switch and regulator] or an intermittent ground connection will cause the voltage regulator to receive voltage spikes caused by the intermittent connection which in turn will eventually kill the regulator.

[DodgeFreak]

i ran wire strait to the alt, but am wondering do i leave the wiring there or remove it incase the pcm is still tring to regulate voltage or will it not hurt anything?? also i had 12volts on both terminals on the orginal, i just ran a new plug to the alt and then put a short wire into the orgianl reg. plug since it had 12volts to try but i didn't have a regulator right off hand so i'm going to have to get one and see if it works, ran out of time before i got it completed.

[BobS]

You must disconnect the field terminals from the 92 harness whenever you use the earlier pre-92 circuit. Failure to do this usually ends up with repeated failures.

[DodgeFreak]

Ok that's what I figured after I already did it, ill get a new regulator and see if it will work