Help! Electric Gremlin(s)

[bobcarroll]

:ugh I have noticed that while my '67 air coupe (base engine) is running, the interior lights will flicker with a frequency tied to engine revs....the faster the revs the faster the flicker. The ammeter indicator arm also fluctuates with the revs speed in time with the light flickers. The alternator codes as original to the car. Otherwise, radio, etc does not seem to be affected by this and the car runs fine. Any help would be appreciated! Thanks, Bob Carroll, Cincy, Ohio

 

[Hib Halverson]

:ugh I have noticed that while my '67 air coupe (base engine) is running, the interior lights will flicker with a frequency tied to engine revs....the faster the revs the faster the flicker. The ammeter indicator arm also fluctuates with the revs speed in time with the light flickers. The alternator codes as original to the car. Otherwise, radio, etc does not seem to be affected by this and the car runs fine. Any help would be appreciated! Thanks, Bob Carroll, Cincy, Ohio

Time to get out the factory service manual and evaluate your alternator and regulator.

If I had to guess, I'd say you have a problem with alternator, perhaps the diode bridge, but I'd test the charging system, before I'd start buying parts.

 

[LLC5]

:ugh I have noticed that while my '67 air coupe (base engine) is running, the interior lights will flicker with a frequency tied to engine revs....the faster the revs the faster the flicker. The ammeter indicator arm also fluctuates with the revs speed in time with the light flickers. The alternator codes as original to the car. Otherwise, radio, etc does not seem to be affected by this and the car runs fine. Any help would be appreciated! Thanks, Bob Carroll, Cincy, Ohio

Does your vehicle have an external, mechanical, voltage regulator?

 

[Hib Halverson]

If it's a 67 and original, the reg. will be external.

 

[bobcarroll]

Yes, the voltage regulator is a Delco unit mounted on the inside drivers side fender well. I understand these may have date codes but I couldn't find them. Am taking the car over to my Vette specialist for exhaust replacement and will have him check out the alternator and voltage regulator. Thanks! BobC

 

[LLC5]

Yes, the voltage regulator is a Delco unit mounted on the inside drivers side fender well. I understand these may have date codes but I couldn't find them. Am taking the car over to my Vette specialist for exhaust replacement and will have him check out the alternator and voltage regulator. Thanks! BobC

Those regulators are usually mounted with rubber grommets and need a good external ground source to function properly. They also need a good battery positive side voltage supply to them with no voltage drop to the regulator. What is the voltage at the battery at idle and at 2000 rpm's?

 

[bobcarroll]

Those regulators are usually mounted with rubber grommets and need a good external ground source to function properly. They also need a good battery positive side voltage supply to them with no voltage drop to the regulator. What is the voltage at the battery at idle and at 2000 rpm's?

Thanks LLC5.......I'm going to let my Vette guy (NCRS Instructor) figure it out. Electronics are not my strong suit. BobC