: 1969 DeVille - Voltage Regulator - Original Part Number

04-17-11, 11:15 PM
I look at Rock Auto and there are a billion Voltage Regulator's. Many with various part numbers.

Can someone PLEASE tell me the part number for the original voltage regulator so I can get the correct one?

Story: I ordered an AC Delco C635 to replace the original voltage regulator that wasn't regulating well and causing my Gen light to come on at idle. I installed the new C635, started up the car and had smoke pouring out of it for the first 3 minutes. Then once that subsided it seemed to me maintaining about 15 volts at the battery at idle and at higher rpm. So I took it for a test drive and it went well until I was on the way back home and when I'd let of the gas to coast into a stop sign or stop light I could hear it start whining and the "GEN" telltale would start to get redder and redder and then go away once I either re-accelerated or would reach some point of regulating the voltage itself. The whining/chattering from this C635 is just awful. Perhaps its the correct replacement part and I got a DUD?

04-18-11, 04:42 AM
I don't know if you're going to find an original-type VR anywhere like Rock Auto. Pretty much everything off-the-shelf these days is, I believe, solid state. I've been doing some digging myself, I want an original one also, but I've got a solid state one in there now. I DO have the original one, I can go get it and let you know what the part number is. I think your best bet for this is E-bay. The problem with the mechanical ones is they need to be adjusted, and there are some very specific tools necessary for doing this, the factory service manual refers to them for the process. It's probably possible to put one in and adjust it using a meter, but to be correct, you'd need these tools.

I'm very concerned about the smoke, what type of smoke, electrical? You need to check the lead from the battery to the alternator. If this is bad, it can cause poor charging, and can also cause the alternator to blow. Specifically, it would be good to remove the terminal from the alternator and see how the connection is to the wire. Another thing to check I think is the lead from the alternator to the VR, this is a fusible link, and is intended to blow to avert more serious problems. I just went through this whole process last month, I'm sure we can get you going. You should have a FSM though, to go through all their troubleshooting steps. My first suggestion is to go to Autozone and get a shelf VR and hook it up, just to see how it runs with that. They're only about $15. VR NEEDS to be grounded well to work properly.

04-18-11, 09:20 AM
Great info, thanks!

I looked over the existing mechanical VR (Delco Remy) pretty well but found no indication of a part number. I'd like to know the OE part number so I can be sure that any newer mechanical VR I purchase is the correct one.

I'm not opposed to throwing a solid state VR in there if it will work. I just want it to work correctly an I'm not concerned about the 'originality'. (I know, BLASHEMY!)

04-18-11, 01:45 PM
I'm very concerned about the smoke, what type of smoke, electrical? You need to check the lead from the battery to the alternator. If this is bad, it can cause poor charging, and can also cause the alternator to blow. Specifically, it would be good to remove the terminal from the alternator and see how the connection is to the wire. Another thing to check I think is the lead from the alternator to the VR, this is a fusible link, and is intended to blow to avert more serious problems.

The smoke was kind of white smoke pouring out the bottom of the VR. Didn't smell like electrical or burning fluids and went away after a couple minutes... The instructions that accompanied the VR said to run it and also turn on the headlights and other accessories to draw electricity and stuff. The VR didn't get hot or anything. Kind of weird actually. Which is why I just played it off because monitoring the voltage at the battery it maintained a steady voltage of 15 volts between idling and revving the engine. Like I mentioned, when I went on my test drive, everything was GREAT for the first half. Then once the car was "warmed up" the VR started whining and the GEN light started appearing whenever I'd let off the accelerator and begin braking. It would reach a crescendo, then the sound would cease and the GEN light would go out. I could also make it cease, by tapping the accelerator again. When I returned home and things cooled down, I attempted to recreate the problem but it performed perfectly again. Second test drive, fine for the first 10 minutes, then started up again all the way home.

Again, any help with part numbers of the OE VR or the correct part number for a replacement VR (mechanical or solid state) would be hugely helpful. The Caddy is laid up in the garage until I can get it fixed and that's just plain sad!!

04-18-11, 02:26 PM
I agree, I just had mine torn apart for 10 days, missed a whole bunch of nice days too. Got it back together last night at 9:30, just in time for the April snow to move in ha ha. I still haven't been able to get to the VR, but my guess is that these are a very common part, and probably generic to most old GMs. When I was having the problem, I walked right into the nearest Autozone, asked for the part, and they had it in stock. Amazing. I'm pretty sure from what you're saying that there's a problem with the VR you got, or maybe it's not hooked up right? I would double check that, not saying you did it wrong, but sometimes these old cars can be finicky. You might want to make sure the terminals are nice and clean. I took each terminal out of the connector and cleaned it with fine sandpaper, to remove any corrosion.

04-19-11, 11:41 AM
OK, I stopped into Autozone on my way home yesterday and picked up a solid state VR (part number VR715). I replaced the terminal on the ground wire that connects to the chassis of the VR. I removed a ground that was attached to the frame right in front of the battery, sanded that down, sanded down the terminal and then reattached that. Sanded down the VR wire connectors in the wire harness. Got a new capacitor/condenser from O'Reilly Auto Parts (part number G137) and installed everything. Checked for good ground at various locations. Everything looked good....

Checked battery voltage before starting, 12.6 volts... Started it up... Checked voltage at the battery at lowest idle position, 14.5 volts.... Raised the rpm, 14.5 volts... Cycled the rpm, steady at 14.5 volts... "GEN" telltale indicator would light when the key was in the "ON" position (as its supposed too) and then would go out once the car was started.

So far, so good. The acdelco replacement VR I had installed worked great in the driveway too. But after about 10 minutes of on-the-road operation, it started to flake out. I'm not going to declare victory on this new VR installation until it passes a couple longer road tests. Unfortunately, its supposed to snow up here for the next 24 hours, so I probably won't get to a longer road test until Saturday.

04-19-11, 02:07 PM
Sounds good, I think you're going to be ok. If you're interested in original appearance, the original VR cover can be removed and installed on the Autozone VR. I haven't done this yet because I'm still toying with the idea of buying an NOS mechanical VR and putting that in.

05-27-11, 07:55 PM
Here's my question... What the heck is the small cylinder that is attached to the side of the regulator and plugs into the single top terminal???

Is that the capacitor?

I got the replacement VR from PepBoys - R281Z.
They told me the small thing was an ignition condensor.
I asked why the connector was not compatible and they said cuz it was an old car. I clipped the connector and attached the kind that is sleeved and connects to the terminal.

Then I was cleaning up the wiring and noticed the exact same ignition condenser attached to the Ignition Coil with the connector I just cut off. Duh. Have not even re-connected the battery yet. Can't seem to get answers anywhere.

When I looked in the Haynes manual, there are instructions for adjustment.
From what I read above, that pre-dates solid state and no adjustments are necessary. The part I am replacing is stamped "uni-point" which I assume was a previous aftermarket replacement, but the cylinder I am talking about looks original. There is a number on it, but no dealers have been helpful.

The item is circular - the number is "161919" in a half circle on top, "DR" in the center, and "5MF" in a half circle on the bottom. Can anyone help me? Thanx

05-30-11, 02:11 PM

per 69Chateau's post... I was able to conclude that the part I needed to identify is simply the "Regulator Condensor".

I phoned back the store that told me I was looking for an Ignition Condensor. They told me that all a condensor did was to alleviate radio interferance.

Not trusting them, I went to Oreilly and referred to "G137" per 69Chateau's post (Thanx for your ellaborate clarity). Oreilly was going to have to special order the part, but the salesman there told me the same thing about the condensor. He said that if I had already altered the connector on the Ignition Condensor I may as well just keep what I have.

That sorta sounds right and sorta doesn't. I'm concerned about loads and purpose and whether what I was told was accurate. On the other hand, there's no sense in trashing a component that will work perfectly fine now.

(Sidenote - surprisingly I've found Pep Boys to be cheapest on parts with Autozone second and O-Reilly nearly double across the board)


Old Voltage Regulator Top

Old Voltage Regulator Bottom

Old Voltage Regulator Side by Side with New Voltage Regulator

Condenser connectors - Pre Alteration

05-30-11, 05:36 PM
Your old regulator is not the original one. It has been replaced.