I noticed the other day that when the car is idling, the interior lights / headlights flicker. When I raise the RPM's, the flickering increases as well, As the RPM's rise higher, the flickering goes away (not sure at what RPM as I don't have a tach). When the ignition is turned off, the lights are fine (no flickering). I suspect it may be either the alternator or the voltage regulator. Any thoughts on how to test or confirm the flickering problem? Erik '71 Buick GS 455 Convertible
Remember how a voltage regulator works- it's basically an on-off switch that turns charging on below a certain voltage, and off above a certain voltage. It is the nature of this arrangement that you'll get higher voltage when charging, and lower voltage when you aren't charging. Therefore, your car is going to have varying voltage depending on whether the regulator is "on" or "off", causing some flickering. -Bob Cunningham bobc@gnttype.org
had same problem I had the same problem with my '71. It was mostly just annoying as hell, but when I did the radio switch, I ran the ground to the brake pedal main ground. When I was down there, things were nasty, so I cleaned up the metal and connecters, to my surprise the dash and interior lights no longer flicker. Nor do the headlights, tho I still have the dim/bright problem that's common I guess. So try lookin at that ground spot, electrical gremlins are bad bad bad.. :af: Scott
Thanks guys. The flickering that I'm experiencing occurs vary rapidly. In other words, the interior lights / headlights flicker many times a second at idle. When I bring the rev's up, the flickering increases. What weird is that when I first start the vehicle and let it idle for a minute, there is no flickering. After a minute or two, the rapid flickering (per second) starts. Any further ideas? Thanks, Erik 1971 Buick GS 455 Convertible
last year i put a new high amp alt in my car due to the amps in my trunk. Everything was good for about six months but now i have flickering just like you describe. A buddy had a chrome alt for a case of beer so i put it on but it didn't even charge so i had to put the current one back on, but while it was off i noticed the shaft/rotor/whatever was movable in and out. anyways, i would be laying blame on your alt, i am on mine , but i guess i also have internal regulator so who knows! (just thought of that) p.s. not really a problem for me right now as intake and heads are sitting on garage floor. damn head gasket!
try this it is normal to see a fluctuation in light brightness,but the pulsing flicker you describe is probably one of these:1 poor ground,make sure the neg batt. post is grounded to the block,then from the block to the frame,then from the frame to the body.use jumper cables to double ground all this and see if problem persists.2 points in regulator(actually weak spring)could be chattering:3 bouncing brushes in alt,this is not likely.....i would look for a poor ground first.o No:
