ROSHX7

What do these signs mean? I was flippin' back and forth today, turning on and off my headlights and noticed how my RPMS drop and struggles and my idle gets worse, when I turn on my headlights. Its OK when I turn it once so just the other lights are on, but once I turn the headlight switch all the way so the headlights come on, it does that. I just replaced my Alternator belt myself, could it be its too tight or not tight enough?

Keith

Not a simple question there. If the belt was too loose, this problem could happen because the belt will slip more with increased load, dropping the voltage at the battery. RX7's do not like this.

If the belt is tight enough (or too tight), turning on the headlights increases alternator load on the engine. Therefore, an rpm drop is normal. Mazda corrected this by inventing the BAC valve. Your engine still has one, doesn't it? If it does, the BAC valve should open up some more under command by the ECU, letting more air in and picking the idle back up. Bad BAC or ECU???

If the belt is too tight, the alternator will wear out prematurely, but everything up to that point will be ok.

Of course, this could not be related to belt tension at all, maybe the alternator is failing. A voltage check would be in order.

Irv, Keith's dad

ROSHX7

Keith's DAD, thanks! for the comprehensive diagnosis...I'll check out all the stuff you mentioned. I think its either the BELT problem or my BAC is f'ed up....cause I know something not right it.