i'm pretty sure the alternator is bad on my b20, when i shift gears my lights dim then brighten back up. i was just wondering if this would have effect on my idle too. when i come to a stop my idle will drop to like 500-600 then slowly raise back up to 850-900. if not the alternator do you guys have any suggestions on what it could be? thanks ahead of time for your help!

 

anyone??

 

I suppose it's possible for the alternator to be the cause, but more likely it's the victim of some other problem.

Your idle can fail to hold steady for any of a zillion reasons. Sticky AIC valve? Vacuum leak? Bad plugs or wires? Whatever causes it, the alternator is not spinning fast enough & that's why your lights dim.

 

thanks jim, anyone else??

 

yes it does. I had an old toyota at one point and the alternator went bad on it. It would idle rough and feel like it would stall out unless I keep my foot on the gas pedal but if you alternator is going bad you should be getting some lights in your dash too. Usually its the battery and something else. Get it checked out first before you start replacing parts. Could be bad battery, vaccum leak somewhere. etc..