its weird..my friends altima had a problem similar to this probably...when his car was stopped and the heat was on high, the force of heat coming out was really low compared to when the car was in motion. he had a radiator problem.

i dont think my heat is much lower when parked than in drive, maybe a little less but thats probably normal but my gauges dim a lot more when my car is parked and my foots not on the accelerator..even when im in park adn i press down on the accelerator a little bit, the gauges get brighter than when i was idle...anyone else notice this in their cars? i just had my coils changed a couple months ago..and battery is new.

 

alternator is GOING.. my moms car does the same thing headlights will get really bright when you step on the gas good thing were getting rid of her car and getting a G35

 

I used to happen to me, now its gone. I didn't do anything... I noticed it only happenes in when lots of moisture outside.. rain, snow.. I would say its Alt when its constant, otherwise I dunno what else it might be..

 

My car has been doing that too. Not sure what it is.

 

yeah it happened the other day when it was raining/snowing outside..also, its not the headlights, its the gauges IN the car..

 

mine does it too. changed my battery lately and its still doing it. could it be the belt to the alternator?

 

any thoughts on whats the cause of that?

 

I doubt its anything. It probably slows the fan speed down so as to not use to much engine power ad idle.

 

I agree MacAlert... Every car I've ever owned (including my max) has shown fan speed drop when the car is at idle...

 

Do voltage test on your altenator. A healthy alt. should put out 13.8 volts with accesories on. Also might want to replace your battery cables, the corrosion in the cables cause resistance and thus less voltage between your alt. and battery.
Also might want to check your idle speed.

good luck!

 

my car does the same thing ive noticed. anyone else notice their headlights dim when the abs kicks in? If im driving at night in the snow and try to stop hard my headlights dim when the abs kicks in. Today i was driving and went to move my seat up a bit and noticed my lights dimmed too. though i had the headlights on, the rear defroster, my heated seat and the stereo goin but not turned up to loud.

its been doing this for a while though. if its sitting in park and i tap the gas i notice my headlights get brighter and the blower goes faster.