Z/YA

iTrader: (36)

Ok I have a 2000 Z28 and its a M6.
When out at night when the headlights are on and you get on it and rev to 5K or higher my headlights will dim considerly like they are not getting enough voltage from the alt.
Now last year I was having a problem with the car eating alt. after I replace about 4 of them (All of them were AC Delco) I checked everything I could think of and could not figure it out, so I took it to the Dealership and they messed with it and it turned out it was the computer that was messing up and overworking the alt. and burning them up. So they putt in a new computer. This was over the winter so I did not really start to drive the car till now.
So now the car is not eating alt. but just a WOT the headlights will dim.

99T/A_Marine

iTrader: (1)

I have the same problem but just figure it to be the cause of running the motor hard and it sucking a shitload of power.

Bowtie Boy

+1
What kind of battery do you run?

Z/YA

iTrader: (36)

Ok so I see its just not me.
I have a new AC Delco battery.
I asked at the GM garage a couple of days ago, and they did not have a clue why it would be doing that. They said to check a few connections and see if any are pulling loose when the motor is touqureing up, but I highly doubt it.
If anyone figures this out let me know

LSex

iTrader: (1)

My F150 did that when it got up in the rpms, the alternator was basically shutting down completely when it happened the battery light came on and everything. If it's as bad as that it's a sign that the alt is nearing the end of it's life, the F150 lost it's alt bought a half year after I noticed it happening, had I never floored the truck at night I never would have even noticed it, it only happens when the engine was revved hard.

Are the lights getting progressively dimmer as you rev higher or is it like a switch?

99T/A_Marine

iTrader: (1)

I've got an Autocraft Titanium. My alternator is a remanned that's been in for about 2.5 months so it's not it. Voltage stays good. It doesn't seem to be hurting anything so I'm not too worried.

FiredUpZ28

Maybe a bad diode in the alternator. Do you have any A/C voltage at the battery? Leaky diodes can do funny things.

CamaroFan71

iTrader: (2)

I have a brand new alternator and new idler pulleys and mine does it. I figure its belt slippage at high rpm's doing it.

Z/YA

iTrader: (36)

I was kind of thinking the same thing possibly, about the belt slipping. I have noticed some power steering fluid on the garage floor, so maybe that is getting on the belt and making it slip at high RPM.
I am putting a cam in the car in a couple of weeks and I would fix the leak then.

bjamick

iTrader: (31)

Ya check your tensioner to make sure its not weak. Does your voltage guage show low when this is happening?

MTN_Z

iTrader: (7)

I have the same issue. I was going to change my alternator but I was also gonna replace the exciter wire. I guess replacing the belt and tensioner wouldn't hurt anything so I may try that as well. I'm hoping it's just the alternator.

99T/A_Marine

iTrader: (1)

P/S fluid could be dripping into your alternator brushes and slowly killing your alternator. Did it to mine about 2.5 months ago. Leaked from the high pressure hose going for the pump to the rack.