Why do my lights fluctuate between bright and dim?
 

HELP! The headlights my 74 Dodge Dart, with a 360 cu inch engine, fluctuate between bright and dim. When the lights go dim, the dash ammeter gauge also drops below normal. Other than the installation of a high performance alternator, the electrical system and components are for the original slant six engine. Got any ideas?

smith -

Did they do that before the "HP" alternator?
I can think of a few things, none of which are good ...
First the new alternator might be bad (usually a diode thing). P\By pass the alt and see if it still happens.
If higher amperage, your old wiring may not be able to handle it, and thing can get worse in a hurry. Does anything smell funny?
Lastly, the ammeter may be fried/frying. You can by pass it and see what happens.

Archer

Sounds like a ground issue, check an verify all your grounds.:)

I agree... And all good points.. :)


Here.... I'll turn you on to some good reading...:)
http://madelectrical.com/electrical-tech.shtml

My vote is for the amp gauge, and poss a ground. Check the grounds on the rad core support for the headlights

Thank you everyone for your ideas. Will check out each suggestion see what happens.