hi - noticed this a few days...trying to figure out if it is a loose belt or a bad battery...when i am at idle with the AC on i notice the headlights dim...when i put it in neutral and give her a rev the lights get brighter...when i turn off the AC the problem goes away...so is it due to the strain the AC puts on the engine? or is it a bad battery...the previous owner just had a new alternator put in before i bought the car a few months ago so i don't think it is that..and i'd guess it wouldn't be the belts if a new alternator just went in, so i am betting on the battery but wanted to see what you all think...

 

The accessory drive belt is held in place by a spring loaded tensioner so that is not the first thing to consider. It usually fails by breaking.

Battery or alternator/regulator can be quickly tested at your friendly, neighborhood auto parts stores.

 

excellent - thanks

 

i changed the battery with one from pep boys..a bosch one...and the problem went away no more dimming lights ...thanks for the info on the accessory drive belt

 

hi all...my issue turned out to be my belts needing to be replaced...once they were replaced the issue i mentioned above is gone!