check engine light comes on... i looked around couldnt find anything saw that my volt meter was reading kinda low but i cant stop so i ignore it and keep driving, as im driving voltage meter drops all the way... i get it home runnin on just the battery and replace tha alt. well that doesnt work becasue now my volt meter is pegged at 18 so i take back that alt and get a good one from napa and same issue. so i check my cables the ground and power to the batt are tight, i tested batt its still good. i have a 400 mile trip back home tom and need my truck running asap... any ideas and suggestions please!

 

guy at the local parts store says he's been down that road and theres a chip like object thats inside the pcm and it controls the voltage, he thinks thats the issue....??? could this be true? could it be the black box with the wires runnin off that bolt onto the alt..?

 

Charge is controlled by the PCM that is true, perhaps you burnt something up.

Worst case scenario, change it over to an external regulator, not hard to do, check user Infidels photo gallery for a schematic.

 

Check the main body ground on the core support by the battery.

The black box is just a junction block, nothing mysterious in there.

The regulator is part of the PCM.

It's possible that the field control wire is shorted to ground. It's the dark green wire on terminal "C" of the alt. Check with a test light to see if it is a good ground (key off).

 

Go here https://www.dieseltruckresource.com/...n&onlynewfaq=1

 

ok guys i just started un plugging things and got somewhere. coming out of the black box theres a wire that goes to the starter its good. the ground is good too. so is the other thick black wire runnin over by the air filter but the bundle of about 4 wires all colered controling the a/c i think is bad. im not sure where its bad at tho, i just unplugged sacraficed my a/c and went driving, so far everything is good, should i keep headin home? my trip also just got longer its going to be about 700 miles?

 

ok back again. trucks in the shop still running high volts when i plug the bundle of colored wires into the plug near the intake, the mechanic cant fix it. any ideas?

 

It sounds like it's charging at full capacity, either the PCM can't read the current battery voltage or the voltage regulator (in the PCM) is toast. Double check your battery connections again. If it is the PCM you can install an external voltage reg pretty easily.

 

guy says thay have narrowed it down to it bein inside the black box that bolts to the alt. ?? and dodge discontinued them!!! so im pretty sure there right because theve had the truck for 3 days and have been workin on it non stop its costin me an arm and a leg! so where can i get a whole new harness???

 

Just bypass the PCM and install an old style regulator. There's directions in the 1st gen sticky.

 

thanks

 

can i get a part number for the eletronic volatge regulator shown in the link above!?

 

Part number is on the unit.

If you're still in a rush, the nearest parts store will have an aftermarket one.

 

I've been told the part number in the picture is no longer available.
Doesn't matter though, any 12 volt regulator, electronic or old style will work.