lenticular

Ever since I've had my 993, the headlights dim when the revs drop. It doesn't particularly bother me, but I wondered whether it was a sign of something screwy in the electrical system. Any ideas?

Thanks,
John

2ndof2

Unfortunately, it sounds like its your altenator going south on you (in a bad way)

If thats the case, rebuilds with a core charge/refund is the way to go IMO.

Marlon

Do you have a single pulley system?

allill

It's probably the alternator.

AOW162435

John,
Where are you located? If nearby, I'll gladly help install the new alternator. I just replaced mine with a Porsche-rebuilt unit that I purchased from Sunset. Cost was $290 (I think) with a $40 core charge. Unless you have debilitating OCD tendencies like me, the swap is fairly straightforward and should take a couple of hours at most.


Andreas

lenticular

Thanks everyone! The weird thing is that it has been this way as long as I can remember. I'm thinking that as it gets worse, I'll eventually get a dead battery, right?

Thanks,
John

richardew

Hmm. That's not what happened when my alternator died.
The alternator charges the battery and the car's electrical systems run off of the battery. I would check the battery as it seems it's not putting out (hmm, did I every date your battery) and the battery is not holding the charge.

Marlon

...single pulley system???

NOH20

I know on my '86 I needed to replace the voltage regulator to cure that same problem. OK flame me....do we have a voltage regulator on our 993's??

richardew

It does, part #
928.603.142.00

AOW162435

One more time, please.


Andreas

Mike J

It sounds like a battery rather than the alternator. If you have a RS pulley system (look at your fan on the engine...does it have one belt or two running to it?). If it has just one you likely have an RS pulley so then its common that the lights dip since on idle the alternator does not spin fast enough to keep up with the current draw.

If you have two belts the alternator should keep up with current draw on idle if the battery is in good shape since its used for supplemental capacity. If its not holding a charge very well the battery may not supply enough supplemental current and the lights dim.

Cheers,

Mike

Marlon

...badda - boom -- tish!

lenticular

Oops, missed that. It is a dual pulley system.

-John

SPIKES

sounds like the battery...my car is not used often and on occasions my car would want to cut out. it starts with the stereo cutting off and also the a/c cuts out....sounds like a short in the dash. i also noticed when i parked the car that the headlights were dimming/flickering on idle....i checked the ground strap and keep a trickle charged on the battery now and so far so good...