another flickering headlights post advice sought

[Kurt B]

Headlights flicker at idle, go up to full strength when rpms are higher and the car is revved.
Car has two times now not started when driven for a while at night and just shut off. If I turn off the lights first and rev it, it's likely to start.
After sitting for a day and a half 36 hours or so, it failed to start this morning, but has started for lunch today and probably will this afternoon.

Should I just get a voltage regulator first for 80 bucks and then see if the problem is rectified or go straight to an alternator/voltage regulator combo?

No, the alternator light has not come on at all or anything.

[RoninLB]

so what's the voltage??

[Kurt B]

Dunno I guess I should measure it?

[john walker's workshop]

voltage regulator bizerk maybe. very common on the 90A units in carreras. do the headlights and dash lights flicker at steady throttle, like on the freeway? being that it's a alt/reg unit, the whole unit should be replaced.

[RoninLB]

Originally posted by Kurt B

I guess I should measure it?

yeah Kurt, maybe.. and not for nothing but that DME is kinda expensive.. like an over-voltage could fry it.. and a $30 interior voltage gauge would warn you of a problem.. cause your alternator won't respond to over-voltage..............Ron

[Kurt B]

okay, and no, they only flicker at idle. they flick with the rpms basically--engine idles down and the lights go dimmer and so on...so, I should replace them both.

[1982911sc]

I have posted this some while back...I have the EXACT same problem Kurt that you are describing above. I tested the alt and battery, both indicated normal voltage. I had my SO in the car giving me some RPM's while I put the meter on the battery. It always came in at a safe range? It is strange the headlights intensify with the RPMs of the car up to a point and just stay at that strength. I still have not done anything yet and it seems to be running fine, never any start up issues? I had all of the alternator replacement advice as well? I am not sure what do do at this point?

[BGCarrera32]

Alternator is suspect...my Carrera did the same, required rebuild.
Professionally load test battery on a hydrometer. Mine required replacement because the alternator toasted it. Also, run leads to battery from a digital voltmeter, go drive around, watch digital readout in car for extended test period at operating temp (15 min after startup or so). Sounds nuts I know but just trying to cover the bases...they can get funny when they get warm from what I hear. Watch readout as lights flicker. Also check ground connection to engine case behind alternator for corrosion at case stud when pulling the alternator. And of course, don't forget the big ground strap forward of the tranny mount.

-BG

[david914]

Sounds to me like your alternator has one or more bad diodes. Time for a rebuild.