OK, so I finally get this car running really good, and I have a new issue. Nothing major (I hope) but just in case, here goes... Sometimes, and of course not all the time, If I accelerate real hard, my headlights dim and my abs/inop light comes on. No noticable decrease in performance or anything when this happens, just the light and a flicker. I don't remember now if the interior gauges flickered too or just the headlights, I'll have to watch next time but I know at least the headlights do. I thought I read somewhere that the abs sensor is on the axle housing..not sure what significance that would have if true, or why it would cause the headlights to dim, or what. What could be causing this to happen? A short somewhere that only shorts when I'm really hitting it? Anyone hear of this one before?

 

Have you had the battery and alternator checked? Sounds like maybe the car is starving for power when the spark plugs start drinking that juice

 

My guess would be a slipping belt if its just on accelerating....

 

The bat I know is good, I just charged it when I replaced my opti a few weekends ago. It also starts on the first crank with no problem. I can test the alternator and battery though. Now if the belt is slipping a little under hard accel...then the alt isn't making full power and that could cause electric issues I suppose, but why would that trip the abs light? Maybe the abs sensor is detecting the drop in voltage? I'll check the belt and the alt/bat and go from there, easy enough to do.

 

Many folks have a busted battery hold down clamp. I've seen the battery tip backwards and momentarily short the positive terminal during hard acceleration.

Look for tell tale signs of shorting by little burned spots behind the battery.

 

And another sorta "weird" thing that may be causing this, (believe it or not), is the alternator field wire.

If your car has "older" (i.e. worn), OEM motor mounts, the engine can lift on the passenger side during hard acceleration, and actually stretch the alternator field wire. The field wire is the little maybe 14 or 16 gauge wire that clips into the back of the alternator, NOT the large 6 or 8 gauge alternator output, (i.e. "charge") wire.

Check for any tension on your field wire during normal idle, and if there is some, you can bet that wire is being stretched during hard engine acceleration.