fireball661957 wrote:

> I have a honda accord 2004 and when the air conditioner is on the lights
> dim for a brief sec.about every 12 to 15 sec.when the fan starts up it
> even does this when the motor is cold . I have taken this to the dealer
> and they say it is a normal thing for this car. Does anyone else have this
> problem?
>

This would be consistent with an extra electrical drain on the system,
much like when you turn on a room A/C, lights on the same circuit dim.
With a car, there is the added factor of the extra mechanical drain
caused by the A/C compressor kicking in that slows the engine slightly,
thereby reducing output from the alternator. If you listen to the engine
carefully, you can actually hear it.

Electric motors have a very heavy initial drain when they first start
up, which is why circuits with large motors on them require delay fuses
to prevent them from blowing prematurely.