Electrical Issue

[604CruisinCroat]

I have a new alternator (90 amp) and new battery. Today I noticed when my car was idling, my wipers were not as fast as when I accelerated, and also my lights were dimmer at idle, but once I accelerated, the lights would brighten up. I have no clue why this is happening. I hope it's the battery and not the alternator, but maybe it's something else? Thanks.

 

[luv2rallye]

Your battery is going, perhaps a dead cell. The alt. at idle can't provide enough power to charge it in it's poor condition (battery is demanding more current than the alt. can presently put out at that speed) so the voltage drops.

 

[604CruisinCroat]

Thank you.
Anybody else agree with the above comment?