Voltage Regulator adjustment

[Tom M.]

Is there a way to increase or decrease the amp to a voltage regulator?

Thanks,
Tom M

Found in archives

[Jim L.]

Re: Voltage Regulator adjustment

What is it you are trying to accomplish?

The current which flows through the VR on the way to the battery and/or other loads is determined by those loads up to the MAXIMUM limit established by the VR.

[Tom M.]

Re: Voltage Regulator adjustment

Jim,
I noticed my lights are brighter under increased RPM's and was thinking the voltage regulator was not charging enough.

[Edward J.]

Re: Voltage Regulator adjustment

Tom, check the battery voltage - without the car running,a healthy battery should be 12.66 , also check the voltage with car running, voltage should be from 13.5 to 14.5, ideal would be 14.2 with a healthy battery this is about where voltage should be. Brighter headlamps on accel. does not always mean there's a problem. make sure the idle speed is also correct. if your amp meter needle is constantly maxed out then there may be a regulator problem.

[Jim L.]

Re: Voltage Regulator adjustment

That symptom says that the Voltage is not being well regulated. Before you can conclude why, you need to make some Voltage measurements. Do you have a multimeter (digital or analog) which reads Volts?

If so:
1. Measure the Voltage across the two battery terminals with the engine off. Should be 12.4V to 12.5V

2. With the engine idling, make the same measurement. If you have a C1 with a generator, you are likely to see a little less than 12.4 because the generator isn't charging. OTOH, if you have a C2 with an alternator, you ought to see around 14 Volts at idle.

3. Increase engine speed to, say, 2000 RPM and repeat the measurement. Regardless of alternator or generator, you should see 14-ish Volts.

If you measure significantly more than 14 Volts.... like 14.5 Volts or higher.... your charging system has a problem.... might be the VR, could be the alternator/generator also. But there is a problem.

[Leif A.]

Re: Voltage Regulator adjustment

Jim,
I noticed my lights are brighter under increased RPM's and was thinking the voltage regulator was not charging enough.

Your VR may have seen better days. Sounds like it's no longer regulating the voltage coming off the alternator, thus allowing more volts to pass through it and your headlights showing brighter with increased RPM. Do you own or have access to a voltmeter? Easy enough to check the VR to see if it's functioning correctly or not.
Jim and Edward must type faster than me

[Jim L.]

Re: Voltage Regulator adjustment

Tom, I'm lazy and am tired of writing alternator/generator. I want to type one or the other. What year car are we talking about?

[James W.]

Re: Voltage Regulator adjustment

Not trying to hijack this thread but what would be the problem of the car idling fine at 750 to 800 rpm without and other electrical accessories on but when the lights are turned on the car wants to die do to the increased load on the battery/alternator? This on a '65 L79 equipped Corvette with a 42 amp alternator.

Thanks,

James

[Michael H.]

Re: Voltage Regulator adjustment

The original VR are adjustable look in the Service manual on how to do it.

Mike

[Tom M.]

Re: Voltage Regulator adjustment

Jim,
Its a '67. I will check the voltage.

Tom, I'm lazy and am tired of writing alternator/generator. I want to type one or the other. What year car are we talking about?

[Frank D.]

Re: Voltage Regulator adjustment

Yes the V/R should be adjustable if original and it may solve the issue if the procedure is followed...

Also any auto parts store will have a Wells VR-715 solid state regulator for about $28 you can plug directly into your wiring harness as a check to see if it improves the situation.... If it does you have V/R problems....and the Wells unit makes a nice "hot spare" in case the one in the car fails someday.