Lights grow brighter with higher RPM - Why?

[Mach Man]

My headlights are brighter at a higher rev and are dimmer at idle.

My voltage regulator is new. Is it the alternator? Is there a way to test it to be sure before I replace it.

Or....is it some other electrical gremlin in my wiring?

As always, any help is appreciated greatly!

Dennis

[JTS71 Mach1]

Hey Dennis, Some raising in brightness or ramping up as it's been called is normal. To be sure it's normal, and not a problem. 1st check battery voltage (all systems off) with a volt meter. You should have about 12.3 volts on a fully charged battery. 2nd start the car and let Idle about 800 rpm give or take. Recheck battery voltage it should be at least 12.6 volts or above. 3rd raise engine to about 2100 rpm and recheck voltage. You should be in the 13.5 volt range. If your readings differ from these I've listed by more the 1 or 2 tenths. Then you could very well have a problem. A very low Idle 600 or so can change things a lot, and actually cause the alternator not to produce any power, and actually drop below 12 volts at the battery which is never good (discharge). Older charging systems, with seperate voltage regulators were not the best for maintaining steady voltage, and load (lights, heater) caused it to vary even more. After you make these checks let me know what you have and I'll see if I can be of more help. JTS 71 Mach1

[Mach Man]

Great Info JTS!

Thank you so much. I will breakout my volt meter and follow your instructions.

I will report back with the findings.

Dennis