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external voltage regulator install help

43K views 16 replies 4 participants last post by  Mopar1973Man 
#1 ·
I'm going to install an external voltage regulator and will be using Mopar1973Man's voltage regulator mod instructions from his website. In the instructions it states to get an ignition source from the output of the ASD relay. Where is the ASD relay located and how do I connect to the output?
 
#2 ·
The asd relay is in the pdc under the hood. Thats the fuse box if you like behind the drivers side battery. I don't know about connecting to it. I presume Mike means finding a live power source from the asd when the key is on and it goes dead with the key off.
 
#3 ·
Ok...



Just hook the blue wire of the regulator back to the blue wire of the alternator currently. Then the green wire on the alternator you remove and hook up the new green wire from the external regulator to the alternator. But make sure to ground the new regulator or damage to the regulator will occur.
 
#4 ·
Mike, where does the +12V keyed wire get hooked up? Your instructions say the ASD relay. Also, what gauge wire should I use?

Thanks for your help.
 
#5 · (Edited)
Blue wire of the alternator should work too. 16-18 AWG is fine.

As long as the blue wire is hooked to 12V key on it should work. Green wire should only be hooked to the alternator nothing else.

I guess I need to update that article... (updated!)
Mopar1973Man's Dodge Cummins Articles - Voltage Regulator Mod

Stock wiring...
 
#6 ·
Thanks Mike. I'm going to tackle this tomorrow now that the weather is going to finally cooperate.
 
#7 ·
Mike, I hooked everything up like the instructions but I'm having problems.
Turned the key on to wait for the "wait to start" light to go out. Volt gauge only went up to about 9. Light went out and started up. Volts went to about 12 and when the grids came on, it went down to about 10 and then back to about 12 when grids kicked off. Took it for a short drive and the volt would not go over 12. When I got back home, I popped the hood and the alternator was very hot and I could smell it.

Maybe I don't have everything hooked up right?

I cut the 2 blue and green wires of the stock harness that plugs into the alternator and then spliced in the wires from the regulator to the harness so it would make an easy plug in. That left just the cut blue and green wires from the stock alternator harness. I spliced into the blue wire that goes between the regulator and alternator and hooked it up to the blue wire I had cut from the stock alternator harness to get the keyed 12V power.

Am I doing something wrong?
 
#8 ·
Picture of voltage regulator mounted to firewall.



Picture of connections at alternator. Also shows ground wire to alternator from voltage regulator (black wire with red insulation)



Picture of where I tapped blue wire between voltage regulator and alternator to go to blue wire of stock alternator blue wire for keyed 12V.

 
#9 ·
Anybody know what I have hooked up wrong? I need to get this fixed this morning or I'm going to have to put it back the way it was before and deal with the irratic voltage and pulsing gauge/dash lights.
 
#10 ·
Why would one need to put in an external voltage regulator?

Isn't the PCM supposed to do this?
 
#11 ·
This is a poor mans way of getting you alternator back without paying a arm and leg for a PCM replacement because the internal regulator has failed.
 
#13 ·
Well, I need my truck for work tomorrow so I pulled the external regulator and put everything back to stock. I'm not sure what's the problem with the way I had the regulator hooked up.

After putting it back to stock, I started the truck and the volts hovered around 10 and down to 9 when the grid heaters would kick on. After idle for a bit and the grids not coming on anymore, volts held at about 11 volts. The check gauges light and chime came on a few times. When I revved the motor a little, volts would go up to about 12 or 13. Took it for a spin and as long as it was running down the road the volts stayed at 14 to
14.5. When I came to a stop, volts would fall to about 12 until I got moving again. This sounds more like the alternator is not working properly. Gauge lights in the pillar are still flickering like before.

The alternator and batteries were replaced 4 years ago because I was having the same problems as I am having now. Within a year of having the alternator replaced, I started having the same problem and the shop replaced the alternator at no charge. That solved the problem until just about a month ago.
 
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#14 ·
Probably a crap rebuild of the alternator.

Try getting the alternator tested at a parts store.
 
#15 ·
:doh:

I always have the alternator bench tested before leaving the store. Also I have the alternator test for AC noise output and should be less than 0.1 AC Volts. If the bench test has a diode test I have then test performed too.
 
#16 ·
Does the alternator need to be taken out of the truck or can they test it while still in it?
 
#17 ·
Preferred to be removed. That way the alternator is isolated.
 
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