ok, i posted this under general tech and no one answered. we'll try here. turn on headlights and every light 'flickers'. headlights, taillights, interior lights. belt seems tight and in good condition. no excessive slack. i'm guessing bad alternator. this is 87 z28 305 carb'ed. heynes manual says the alternator brushes cannot be changed from 87 and newer. only 86 and earlier can be re-built. true??? thanks.

 

If it was a bad alternator, more than just the lights would be going. Try your radio, gauges, and the car itself wouldn't want to run after a while.

Does this only happen when you turn the headlights on? or do the lights always flicker, even with the headlights off? Then again, considering they're all on separate wires and fuses, maybe it is the alternator. I would go with a whole new alternator instead of just fixing the old one. That's me though, I don't know how deep your wallet runs.

 

May want to check the ground straps, fusible links, and battery cables for tightness. You can get a rebuilt alternator for most any car, regardless of what is in the service manuals.

 

the first thing that jumps to my mind is the actuall headlight switch, that switch if its in pretty crappy shape could cause that to happen, it adjust the brightness off the dash lights and can turn the dome light on and off, and obviously controls all the exteiror lights. if the switc is corroded inside it may be getting a shotty connection giving u ur effect. alternator i doubt it, with a alternator all its going to do is everything will get dim and youll see your battery draining on the gauge. so u can almost role out the alternator unless, something is damaged inside and its hitting and missing, but if thats the case youll be able to see it even with the lights off if you test for it. same with the battery. what you wanna be looking for is, the switch, cables, maybe fuses, something thats tied into the lighting system. your best bet is to get yourself a multimeter and start testing, starting wiggling wires, turn on the headlights and wiggle the sucker see if u can make it better or worse. just for the heck of it if u wanna convince yourself take your car to a garage have them throw a tester on that alternator in 2 min they can tell u if its good or not, most garages will do it for free or like $5-10.

and as far as rebuilding that alternator, it can be more of pain in the butt finding someone that carries the parts to do it, than actually doing it.

 

thank you gentlemen, i'll let you know. by the way, even without the lights on, the alternator gauge bounces up and down. with the lights on, the gauge bounces with the flicker of the headlights. reminds me of my wig-wags on my cruiser. ha!