Another bad voltage regulator?

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Craig Burriss

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How often do y’all have to replace a voltage regulator?
Trying to get my 83 RamCharger on the road again and the new voltage regulator is evidently already shot after being in use for probably 2 hours of run time. Saw the voltage hit 18v at idle from the stock square back alternator.
Back when my Duster had an externally regulated alternator, after a couple miles the voltage would start spiking again.
All of the connections are good, and everything it grounded properly. Could this be an alternator problem? Or just a cheap Chinese junk regulator?
It seems like I have a lot of charging issues...
 
Are you SURE it is not a grounded brush in the alternator? Try disconnecting the connector at the VR it should stop charging. Due to Chinoizaeazization no idea the good/ bad quality of replacements. OEM Chrysler VR's some of them lasted so long, vehicles ended up in the junk yard with the original VR Lots of em in fact

The other issue that can cause over-charging is poor grounding OF THE VR and voltage drop in the harness. The VR MUST see true actual battery voltage.

The last thing is a partially shorted rotor that will draw too much current. Look up in one of the late, say 73 service manuals over at MyMopar (free) There's a procedure for measuring rotor current draw
 
How often do y’all have to replace a voltage regulator?
Trying to get my 83 RamCharger on the road again and the new voltage regulator is evidently already shot after being in use for probably 2 hours of run time. Saw the voltage hit 18v at idle from the stock square back alternator.
Back when my Duster had an externally regulated alternator, after a couple miles the voltage would start spiking again.
All of the connections are good, and everything it grounded properly. Could this be an alternator problem? Or just a cheap Chinese junk regulator?
It seems like I have a lot of charging issues...

Once every 20 years! Maybe!

There is another issue!

Have your Meter in hand as Del will surely help you!
 
Once in 54 years, you have something else causing your issue
LOLOL My Mopar swapped old FJ-40 Landcruiser had an OEM regulator out of "something" I pulled off and was on the LC when I junked IT. "A long time!!"
 
Just found a household wire nut holding some power wires together, so I’m going to do some repairs before I even hook the battery back up lol.
Will report back with my findings on the VR
Thanks for the advice!
 
Most charging issues are caused by the regulator not being grounded good. I like to remove the sheet metal screws and install regular bolts with nuts on the back. Much more reliable. Might not be your problem but its always the first thing I check with a charging problem.
 
Most charging issues are caused by the regulator not being grounded good. I like to remove the sheet metal screws and install regular bolts with nuts on the back. Much more reliable. Might not be your problem but its always the first thing I check with a charging problem.
Same here. After leaving a friend of mine's Memorial in May we had a no-start condition caused by a low battery everything was brand new. Standard motor products Vr. China. What up to advance the next day and got some gray piece of crap it was from China too. Where's The Summit in order to new reproduction Mopar with upgraded Electronics made in USA unit they're $47 but well worth the cash to me
 
Same here. After leaving a friend of mine's Memorial in May we had a no-start condition caused by a low battery everything was brand new. Standard motor products Vr. China. What up to advance the next day and got some gray piece of crap it was from China too. Where's The Summit in order to new reproduction Mopar with upgraded Electronics made in USA unit they're $47 but well worth the cash to me
U purchased mopar reproduction @ Summit ?
 
Thanks Hoss , I may buy one because im running a new Junk silver one mentioned from Advance auto parts so China made = on the side of the road any min , AC delco offers one also but I'm close to summit so I will buy one and install and put china junk in glove box for back up.
 
Thanks Hoss , I may buy one because im running a new Junk silver one mentioned from Advance auto parts so China made = on the side of the road any min , AC delco offers one also but I'm close to summit so I will buy one and install and put china junk in glove box for back up.
Right on Brother! Must be nice to cruise out there, and kill the shipping costs? Any show room Mopar engines? Man ,I miss speed shops. They were all over back in the day...
 
Right on Brother! Must be nice to cruise out there, and kill the shipping costs? Any show room Mopar engines? Man ,I miss speed shops. They were all over back in the day...
Had a Demon down there
Mcdonough branch about 6.months ago
 
AC Delco offers one also it may be the best parts store offering
12SI AC Delco replacement for my Jeep
Even had a GM p/n on the box.
Junk not made to factory GM spec's. Not even close. :(
When it comes to replacement parts its all a crapshoot. QC isn't even close to what OEM ever was, even at its low points.
Another alternator problem
more pics here
Stop in for a cup of coffee

Craig. Sounds like like you're on the right track.
 
Thanks Hoss , I may buy one because im running a new Junk silver one mentioned from Advance auto parts so China made = on the side of the road any min , AC delco offers one also but I'm close to summit so I will buy one and install and put china junk in glove box for back up.

Did you not take my Mopar Blue 69 down with the Gold Box?
 
Well after fixing tons of issues in the entire wiring harness, the voltage is better, at about 3k rpm it’ll touch 15 volts, but won’t go any higher. I’m not sure exactly what was causing it because so many things were screwed up, but I’m suspecting it was just the connector that plug into it, it was corroded a little.
B081F137-EE35-423D-A5B6-53FF400008B8.jpeg

It’s not an A-body, but shares a lot with them. Thanks for all of the input.
Happy 4th!
 
After letting the truck sit for a couple of months, the voltage has started to go crazy high again. I saw 18v at idle with a multimeter connected at the alternator. When I unplug the voltage regulator, or one of the field wires, it completely stops charging. Unlike an A-body, the field wires appear to be green and orange, but they’re old and dirty and I have deuteranopia (color blind). I tried swapping their positions on the alternator and it didn’t change anything. I also took the VR off and sanded the mounting points to clean bare metal on the firewall and the VR itself. Connector pins are also clean and tight.
I tested the voltage at the VR connector and it reads about 1v lower than actual battery voltage.
When I turn the headlights on, the voltage at the alternator output stud dropped to 14.7v at idle.
It has a brand new chineseium VR
 
After letting the truck sit for a couple of months, the voltage has started to go crazy high again. I saw 18v at idle with a multimeter connected at the alternator. When I unplug the voltage regulator, or one of the field wires, it completely stops charging. Unlike an A-body, the field wires appear to be green and orange, but they’re old and dirty and I have deuteranopia (color blind). I tried swapping their positions on the alternator and it didn’t change anything. I also took the VR off and sanded the mounting points to clean bare metal on the firewall and the VR itself. Connector pins are also clean and tight.
I tested the voltage at the VR connector and it reads about 1v lower than actual battery voltage.
When I turn the headlights on, the voltage at the alternator output stud dropped to 14.7v at idle.
It has a brand new chineseium VR
I had same and similar issues. Jegs has MP USA made VRs. 35 to 45 bucks. Between that, and Redfish helping me w/ ammeter ga, Problem Solved. That, and the crap Chi Com Remanned "lifetime " lol alt from the chain store.. who the hell came up with sending OUR good ol America parts to Commies to reman? That's BS... sorry for rant....
 
After letting the truck sit for a couple of months, the voltage has started to go crazy high again. I saw 18v at idle with a multimeter connected at the alternator. When I unplug the voltage regulator, or one of the field wires, it completely stops charging. Unlike an A-body, the field wires appear to be green and orange, but they’re old and dirty and I have deuteranopia (color blind). I tried swapping their positions on the alternator and it didn’t change anything. I also took the VR off and sanded the mounting points to clean bare metal on the firewall and the VR itself. Connector pins are also clean and tight.
I tested the voltage at the VR connector and it reads about 1v lower than actual battery voltage.
When I turn the headlights on, the voltage at the alternator output stud dropped to 14.7v at idle.
It has a brand new chineseium VR

I still believe your problem is voltage supply TO THE VR. The IGN terminal is the "sensing" and that terminal MUST see "same as battery voltage" and MUST be grounded to zero difference between VR flange and batt neg

IT MIGHT JUST BE the VR connector so if you can rustle up another that might be something. As much trouble as you've had, I'd devise a way to probe THROUGH the connector TO the VR IGN power post directly. If you can find a large needle, etc, this might not be so hard. Devise a way to probe through the rubber (which I do not like to do) and end up with the probe tip INSIDE the circular connector hole that fits the pin.

Then, with key to "run" and engine stopped, probe that to the VR mounting and read the voltage. low, the difference between that reading and the battery reading will be the amount of overcharge.
 
Also Craig, do you have any VRs that you've pulled off that "might be good?" If you are good at soldering, you could directly solder some wire leads (no 18 or 16) direct to the VR terminals, and use that for a "guinea pig." You can wire it direct to battery, direct to alternator, and make a no10 jumper wire from the VR mounting hole to the battery NEG

If you cannot solder and want to spend the money on shipping, send me one, I'll test it, solder some leads to it, and send it back
 
Also Craig, do you have any VRs that you've pulled off that "might be good?" If you are good at soldering, you could directly solder some wire leads (no 18 or 16) direct to the VR terminals, and use that for a "guinea pig." You can wire it direct to battery, direct to alternator, and make a no10 jumper wire from the VR mounting hole to the battery NEG

If you cannot solder and want to spend the money on shipping, send me one, I'll test it, solder some leads to it, and send it back
I’ll have to try this. I think I’ll go swap out the Vr first just in case, because it’ll be free to do. If that doesn’t work I’ll try to wire it up like you explained.
I think I have an old Vr that the backing has melted out out of. No idea if it’s any good. But I’d guess not.
 
The potting is hard to say. On older VR and ECU's etc, the potting sometimes deteriorates, and those all "run warm" so sometimes the potting actually drools out. It may be a potting problem instead of an electronics problem

Also you can tell if the VR is regulating properly to it's set point--regardless of what the battery is doing........by measuring directly from the VR ground flange to the VR IGN terminal. With the thing warmed up (they are temp sensitive) it should measure 13.8--14.2, not below 13.5 and not above 14.5 or so. Some of the shop manuals (MyMopar) have a temp correction chart for the VR voltage

Doing this measurement "gets past" any harness / drop problems and tells you what the VR is actually "at"

Temp correction chart. As you can see the voltage varies quite a bit with temp

voltagechart.jpg
 
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