A few weeks ago I bought a new 2008 Honda Civic LX, manual transmission with A/C.

I've started using the heater now that it's cool in the mornings. I notice that when I turn on the heater, both the AC fan and the engine cooling fan cycle on and off every 15 seconds or so. It's definitely related to turning on the heater. The heater temperature and fan speed don't seem to make a difference.

Is this normal? I can't think of a reason why the engine fans would start when the heater is turned on. If anything, the opposite should happen.

Thanks,
Rob

 

When you select defrost, the A/C runs to dehumidfy the air before it is heated and applied to the windshield. This clears fog off of the inside of the windshield much better than just warm air would. Nearly all newer cars work that way. The older Civics do not automatically link the A/C to the defroster. If you select the floor outlets instead of the defroster it should just be heat then.

 

Hey thanks a lot, you're absolutely right. I appreciate the info.