Gain extra benefits by becoming a Supporting Member Click here find out how!

Classic Performance Products Classic Industries
American Auto Wire
Danchuk Catalog
Hellwig Products IncPerformance Rod & CustomNu-Relics Power Windows

Username Post: Anyone know how to test a REMOVED voltage regulator?        (Topic#361149)
Member #51
Posts: 8906

Loc: Mustang, OK, USA
Reg: 12-25-99
05-27-20 08:22 PM - Post#2795029    

For a car, such as mid-50s/early 60s Chevys that has a Delco 12volt voltage regulator and generator (NOT, repeat, NOT and alternator)-------------- --and with the voltage regulator REMOVED from the car, and on the workbench, does anyone know how to test to see if it is faulty?
Several days ago, the 7yr old battery on the 56 Vette, died. I figured it was due, so I replaced it. with the new battery, everything was fine. Today, I went to start it, and the new battery is dead!!!
Because of the airbox modification that I've done to the 56, accessing the voltage regulator is a SUPER, MAJOR pain. But I finally got it off and on the workbench. In the Okla City area, there are no longer any mom and pop starter/generator shops. They all retired and closed up shop. I have another (believed to be) good voltager regulator, but I do not want to put it on just to see if that fixes the problem (I'm thinking the regulator has developed a direct ground and drained the battery).
SOOOOOOOOOOOOOOOO, if there is a possible way, I'd like to test the regulator to determine if it has gone bad. I mean, after all, it's only been on the 56 for 45+yrs.
I know that John Pirkle was rebuilding regulators and he is no longer with us. But it seems his son continued the business. Anyone know?????????


"5th Year" Gold Supporting Member
Posts: 864
Age: 62
Loc: New Westminster BC
Reg: 09-25-13
05-27-20 09:18 PM - Post#2795034    
    In response to DZAUTO

DZ, I know you are one of the smartest guys on here and you have probably already checked this but...I was Googling what you are describing and I came across this in regards to 56-62 Vettes. It may be helpful?
Steve65 g-gen...

Steve Duncan
66 Impala 2dr Coupe
Not sure of color yet
work in progress

"6th Year" Silver Supporting Member
Posts: 134
Loc: Kentucky
Reg: 04-15-07
05-28-20 08:21 AM - Post#2795058    
    In response to DZAUTO

If you Google "Benchtesting a 12V voltage regulator", there are lots of videos that may be worth looking at. They are not specifically for a '56 Vette, but I would guess that one voltage regulator is pretty much like the next one. Can't hurt to give it a shot.


Member #51
Posts: 8906

Loc: Mustang, OK, USA
Reg: 12-25-99
05-28-20 10:26 AM - Post#2795065    
    In response to fantm2flyer

Yep, I've checked every source that I can think of, no success.
I KNOW that a Delco regulator for a 12v generator (55-62 versions) can (or at least could) be bench tested to determine if it is functioning properly. But the two main mom and pop shops in the Okla City area that could do that are now out of business.

"6th Year" Silver Supporting Member
Posts: 1408
Loc: No. Virginia
Reg: 01-18-13
05-28-20 01:47 PM - Post#2795075    
    In response to DZAUTO

Tom, you may have already considered this:

Because the voltage regulator maintains a constant output voltage regardless of variations in the input (within its specs), any electrical test bench that can measure output voltage and vary input voltage should be able to determine if the regulator is working properly.

Maybe looking for general electrical testing businesses (outside the automotive universe) in your vicinity may help. They likely won't know what voltages to apply, or measure. You will have to tell them, and you may have to tell them how to hook it up.

Just a thought.


Member #51
Posts: 8906

Loc: Mustang, OK, USA
Reg: 12-25-99
05-28-20 04:44 PM - Post#2795096    
    In response to japete92

Got it! Found a place not far from the house. He can test a regulator for a 12v generator, but he has to use a generator to do it. So I took the generator, he then tested the regulator and it's good. Sooooooo, now I have to do deeper trouble shooting to determine what made a direct ground that drained the battery.

FOUND IT!!!!!!!!!!!!!!!
It was a faulty interior light switch at the door. TOOOOOOOOOOOOOO EASY to fix!!!!!!!


Icon Legend Permissions Topic Options
Report Post

Quote Post

Quick Reply

Print Topic

Email Topic

FusionBB™ Version 2.1
©2003-2006 InteractivePHP, Inc.
Execution time: 0.085 seconds.   Total Queries: 16   Zlib Compression is on.
All times are (GMT -0800) Pacific. Current time is 07:59 AM