The Stovebolt Site Forums The Shop Area The Electrical Bay Voltage regulator issues

Hello all,
The 2 year old regulator is starting to become intermittent (mostly on the inop side!). I tested the generator output and it is stable at about 13 volts, and I show only battery voltage on the regulator output terminal. The other night driving home it was inop (with headlights) until about halfway there it started working and charged until I decelerated for a turn and it quit after that. I thought that maybe it was voltage related, but it sometimes works with a charged battery, and sometimes it does not.
My question is what can I check/test inside the unit and get it working again before I buy another. It could be it has been doing it for a while, but didn’t notice it until the days got shorter and I’ve had to drive in the dark.

Thanks, Lee.

Hi Lee,
There are 2 words you need to know regarding voltage regulators...Delco Remy. Another possibility is Standard Parts Co. Both of those were well-made. Find voltage regulators made in America (means you'll either need to get a new old stock or find a good used one dating back to the early 1980s or prior). These things generally last a long time. Somewhere I kept a Standard Parts Co regulator, but I'd have to look for it. I bought it new around 1978 and it was working fine when I switched to an alternator. New one you buy today will be made either in China...or there may still be some around that were made in Brazil. All are junk in my opinion.

First- - - - -disconnect a battery cable! Never do anything under the cover of a regulator with the battery connected unless you're making an adjustment that requires the engine to be running.

Next- - - -use a piece of clean card stock like a strip cut from an index card, or maybe a business card, to burnish the contact points. Two of the point sets will be spring loaded closed, the current and voltage regulators. The third set, the cutout relay, will be "normally open" and will only close when the generator armature voltage exceeds the battery terminal voltage. NEVER, EVER, USE A FILE OR SANDPAPER ON REGULATOR POINTS! They open and close with a slight wiping action, and even microscopic scratches will make them stick.

BTW, the voltage regulator setting AGAINST A FULLY CHARGED BATTERY should be around 14.5-14.7 volts. Do not attempt to adjust voltage unless you are sure the battery is fully charged.
Jerry

Here are a couple of photos of the regulator; it says “made in USA” on it, but I can find no company name. Unlike the original that I replaced, this one has no adjustment screws. All the contactors look clean; the battery contactor (cutout relay maybe?), has a slight bend in it so the contactors do not meet up square. But the contactors are convex anyway, so I don’t think that would matter much. I’ll clean them up just to make sure that is not the issue, and run the truck with the cover off to try to see which one is not working correct.

That's somebody's aftermarket clone of a Delco-Remy (NOT AC-DELCO) with some manufacturing shortcuts that are very obvious. I've never been able to see a few ohms of resistance across a set of points, no matter how closely I look. There is a specific checking procedure used to evaluate the performance of a regulator that only one person that I can remember on this forum has been willing to follow in the past 20-something years. He fixed the problem, BTW. The field current passes through both sets of spring-closed points, so a tiny bit of resistance on either one will keep the generator from charging. The regulator in the photo is adjusted by bending the lower spring anchor up and down GENTLY to change the voltage or current flow where they start to open and close. You cannot see the two spring-closed points operate- - - -they open a few thousandths of an inch and close again- - - -several times a second. I have monitored regulator point operation at times, with an oscilloscope.

There are two types of regulators for GM vehicles- - - -Delco-Remy, and "WRONG"!
Jerry

Did Delco Remy make 12 volt regulator without adjustment screws?

I don't recall ever seeing one like that. The cutout relay adjusting screw has a left hand thread, so "clockwise" increases the setting, just like the voltage and current regulator screws. Ford and MOPAR regulators usually had the "bend the tab" type adjustments. Either one works OK, as long as the guy with the pliers is careful with his spring tension tweaking.

There are places inside all regulators where carelessly creating a short with an adjusting tool will result in an instantaneous "smoke test"!
Jerry

I'm with Jerry. I've never seen a Delco Remy without adjustment screws. And I've seen people get into a real mess trying to adjust them. As I said before, a good one generally lasts a long time. When I say a long time, I've seen some of them last 30 or more years. A substandard one might last a short while and a Chinese one might never work from the moment you unpack it. Good luck.

Those people probably don't have any business working with anything more technical than a ball peen hammer. Adjusting a regulator isn't "rocket surgery", but using the right equipment is necessary, and the correct sequence of operations must be followed. Analog ammeters and voltmeters (not digital) are an absolute necessity. A digital meter responds too quickly to the vibrating points, and the readout will be nothing but gibberish.
Jerry

I bought this one from the local electric motor service company that I have used for repairing starters, generators, and alternators since I moved here thinking that they would sell the best available. I cleaned the contactors as suggested and will see how it does the next time I drive. Thanks for all the help.

Lee.

12v and 6v Delco Remy style voltage regulators are still made in the USA by a company called Regitar. I think they are in Illinois.

I just bought one of each for my '56 Cadillac (12v) and '50 Chevy truck (6v)

6v is part # 231-12020 (negative ground for 1950)

12v part # is 231-12026

I took my generator and regulator into the shop yesterday and both tested fine on the bench. After reinstalling, on the test drive it worked fine for about 6 miles then quit again. I tried turning on the lights to see if maybe putting a load on the system would get it working, but it did not. On the way back home a few hours later, it started working after about 5 miles then quit again when I decelerated at a turn (engine back to idle). So I guess my options are either replacing the regulator again (it is only 3 years old) or doing the conversion to an alternator.

Lee

What brand is the regulator? If it's not Delco-Remy, you might as well join the "It can't be fixed- - - - -I give up" crowd and go with an alternator.
Jerry

There are pro's and con's to staying with the generator and voltage regulator and also going to the alternator.

FWIW, I needed to "adjust" a few comments, so please keep it civil and avoid the unnecessary stuff. Thanks.