voltage regulator
Moderators: Cal_Gary, T. Highway, Monkey Man, robi
- Cav Trooper
- SGT
- Posts: 217
- Joined: Wed Sep 08, 2010 6:24 pm
- Location: SW Ohio
voltage regulator
I was driving the M today and noticed the amp gauge was pegged to the right. My assumption is that the voltage regulator is toast. Are these solid state or do they have points that could stick. I haven't stated to dig into it yet. When I start the truck, the gauge reads in the green for half a minute at most then moves all the way over to the red. Any ideas?
CT
CT
HHT 2nd ACR
Merrell Barracks, Nuremberg, Ger.
1967/68
71st AHC, 14th AHB, Americal Div.
Chu-Lai, S. VietNam
1969
Cav Trooper
Merrell Barracks, Nuremberg, Ger.
1967/68
71st AHC, 14th AHB, Americal Div.
Chu-Lai, S. VietNam
1969
Cav Trooper
Re: voltage regulator
Hi Cav,
I can't tell you much about the regulator....but is the points type....and not solid state. There's an extensive section in one or the manuals that explains how to work on the regulator. I'll see if I can find it tomorrow.
Here's a video about our regulators on YouTube: http://www.youtube.com/watch?v=DcTn9uf6Aqg
regards,
bob
I can't tell you much about the regulator....but is the points type....and not solid state. There's an extensive section in one or the manuals that explains how to work on the regulator. I'll see if I can find it tomorrow.
Here's a video about our regulators on YouTube: http://www.youtube.com/watch?v=DcTn9uf6Aqg
regards,
bob
- Cav Trooper
- SGT
- Posts: 217
- Joined: Wed Sep 08, 2010 6:24 pm
- Location: SW Ohio
Re: voltage regulator
It appears that I don't have that type, must be solid state since it has cooling fins.
Thanks
CT
Thanks
CT
HHT 2nd ACR
Merrell Barracks, Nuremberg, Ger.
1967/68
71st AHC, 14th AHB, Americal Div.
Chu-Lai, S. VietNam
1969
Cav Trooper
Merrell Barracks, Nuremberg, Ger.
1967/68
71st AHC, 14th AHB, Americal Div.
Chu-Lai, S. VietNam
1969
Cav Trooper
Re: voltage regulator
Here is the address and contact info for a place in California that rebuilds the points type voltage regulator.
C P GENERATOR, INC.
1834 S. Figueroa St.
Los Angeles, California 90015 , USA
http://www.cpgenerator.com
phone: 213-746-1060
Fax: 213-746-9469
These people have been doing it for decades. Give them a try.
It's not cheap, but then what is these days?
52 M-42
C P GENERATOR, INC.
1834 S. Figueroa St.
Los Angeles, California 90015 , USA
http://www.cpgenerator.com
phone: 213-746-1060
Fax: 213-746-9469
These people have been doing it for decades. Give them a try.
It's not cheap, but then what is these days?
52 M-42
Re: voltage regulator
Hi Cav,
Yeah, if you have the cooling fins you've got the newer version....which I believe is solid state. I really don't know anything about that one.....but PM Carter....I believe he has one on his M....and that boy is a treasure trove of knowledge.
Yeah, if you have the cooling fins you've got the newer version....which I believe is solid state. I really don't know anything about that one.....but PM Carter....I believe he has one on his M....and that boy is a treasure trove of knowledge.

Re: voltage regulator
Hey Cav,
I just ran across this on eBay....it might be cheaper to buy a new one than have yours fixed....I really don't know.
http://www.ebay.com/itm/VOLTAGE-REGULAT ... 35c74b0ee9
regards,
bob
I just ran across this on eBay....it might be cheaper to buy a new one than have yours fixed....I really don't know.
http://www.ebay.com/itm/VOLTAGE-REGULAT ... 35c74b0ee9
regards,
bob
-
- 1SG
- Posts: 2832
- Joined: Sat Oct 20, 2007 4:35 am
- Location: Norwood, NC
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Re: voltage regulator
The good quality solid-state regulators are by far the best choice. Direct plug and play change out for the old type too. There are some cheap imports out there also; they do work ok, but are not nearly as good as far as longevity of life is concerned.
Charles Talbert
www.mseriesrebuild.com
www.mseriesrebuild.com
Re: voltage regulator
Get your manual out and test the VR to make sure that is the problem. Hate to spend money on a new one only to find that it's something else.
M37s are HMMWV in my world!
- Cav Trooper
- SGT
- Posts: 217
- Joined: Wed Sep 08, 2010 6:24 pm
- Location: SW Ohio
Re: voltage regulator
Unless it's the batteries, I can't see anything else being the problem. All new wiring a four years ago and it all worked until Saturday. I will have the batteries checked today. Truck cranks fine though.
HHT 2nd ACR
Merrell Barracks, Nuremberg, Ger.
1967/68
71st AHC, 14th AHB, Americal Div.
Chu-Lai, S. VietNam
1969
Cav Trooper
Merrell Barracks, Nuremberg, Ger.
1967/68
71st AHC, 14th AHB, Americal Div.
Chu-Lai, S. VietNam
1969
Cav Trooper
- Cav Trooper
- SGT
- Posts: 217
- Joined: Wed Sep 08, 2010 6:24 pm
- Location: SW Ohio
Re: voltage regulator
What can they rebuild on these solid state regs?
HHT 2nd ACR
Merrell Barracks, Nuremberg, Ger.
1967/68
71st AHC, 14th AHB, Americal Div.
Chu-Lai, S. VietNam
1969
Cav Trooper
Merrell Barracks, Nuremberg, Ger.
1967/68
71st AHC, 14th AHB, Americal Div.
Chu-Lai, S. VietNam
1969
Cav Trooper
-
- 1SG
- Posts: 2832
- Joined: Sat Oct 20, 2007 4:35 am
- Location: Norwood, NC
- Contact:
Re: voltage regulator
99.5% chance it will be a malfunctioning regulator when the overcharge condition you described is going on. Attend to it promptly, this condition will kill your generator and batteries in short order if let go.Cav Trooper wrote:Unless it's the batteries, I can't see anything else being the problem. All new wiring a four years ago and it all worked until Saturday. I will have the batteries checked today. Truck cranks fine though.
Charles Talbert
www.mseriesrebuild.com
www.mseriesrebuild.com
Re: voltage regulator
The one down side of solid state regulators is that when they fail there is no repair. However, they are more reliable than the older points type. As its been mentioned, there is a lot of cheap crap out there so spend a few extra dollars and get a good quality part. I might suggest load testing each battery individually. One of them could have an internal short. Rare, but it does happen. I just went through this problem with a new battery on one of my other vehicles. Although the needle on my amp gauge would constantly move back and forth. It took me 6 months and finally talked to a guy at the parts house where I bought the battery and he told me it sounds like the battery has a short. Long story short I took the new battery back and he load tested it and it failed. So he gave me a new battery and the problem went away.Cav Trooper wrote:What can they rebuild on these solid state regs?
- Cav Trooper
- SGT
- Posts: 217
- Joined: Wed Sep 08, 2010 6:24 pm
- Location: SW Ohio
Re: voltage regulator
Pulled the batteries and had them load tested. Walmart tested and said they were both bad, went to Autozone and they tested good. Got a new regulator today and installed. Now the amp gage is in the green again.
Thanks for all of the input.
CT
Thanks for all of the input.
CT
HHT 2nd ACR
Merrell Barracks, Nuremberg, Ger.
1967/68
71st AHC, 14th AHB, Americal Div.
Chu-Lai, S. VietNam
1969
Cav Trooper
Merrell Barracks, Nuremberg, Ger.
1967/68
71st AHC, 14th AHB, Americal Div.
Chu-Lai, S. VietNam
1969
Cav Trooper
Re: voltage regulator
Just adding my 2 cents. When my points regulator went out I bought a solid state one off eBay. I installed it and started it up and the needle went to the green for about thirty seconds then dropped off. Vendor said it is an electrical part no replacement as he said I must have installed it wrong.
I bought a take off deuce and a half 60 amp with the regulator built in and never looked back. Not exactly correct but a much better set up with much more amps. It is military and looks original. I had to change my pulley over and got an adapter kit off eBay that the military used when they converted the deuce. Worked good.
Fwiw,
Mark

Fwiw,
Mark
Mark Ellis
1953 M37 WOW
1967 M101A1
NRA Life Member
USMC Retired
1953 M37 WOW
1967 M101A1
NRA Life Member
USMC Retired
-
- 1SG
- Posts: 2832
- Joined: Sat Oct 20, 2007 4:35 am
- Location: Norwood, NC
- Contact:
Re: voltage regulator
This is a very good way of doing it if staying military matters. If it doesn't matter to you, a Delco-Remy 10SI, one wire set up is easy, cheap, and works very reliable.topellis wrote:Just adding my 2 cents. When my points regulator went out I bought a solid state one off eBay. I installed it and started it up and the needle went to the green for about thirty seconds then dropped off. Vendor said it is an electrical part no replacement as he said I must have installed it wrong.I bought a take off deuce and a half 60 amp with the regulator built in and never looked back. Not exactly correct but a much better set up with much more amps. It is military and looks original. I had to change my pulley over and got an adapter kit off eBay that the military used when they converted the deuce. Worked good.
Fwiw,
Mark
Charles Talbert
www.mseriesrebuild.com
www.mseriesrebuild.com