When I use the defrost selection my electric fan come on and off continuously every 30-40 seconds, this even happens when the car has sat over night and is cold. This issue also fluctuate the battery gauge from above 14 to as low as 10-12 amp when this is going on. I was told to replace the high temp sensor, no help, I was then told it is a computer issue and that it needed to be reprogrammed. I chose to disconnect the fan for now. Besides a computer issue, what else could be the issue?

 

I asked this question awhile back. Apparently this is normal. If you turn the switch to off,you'll notice it won't do it anymore. I find it very frustrating as well and may put my own switch on it I can control from the inside.

 

it is designed like this,it comes on when you select defrost because your ac comp is also coming on,comp comes on to remove moisture from incoming air so there is not moisture build up inside the car.
The electric fans primary function is for the ac,not cooling. it will come on when in ac or defrost,many cars it also comes on when heat is also.

 

yup, normal operation.

you can dis-connect the wiring to the a/c compressor during the winter time to stop the comp. from kicking in and out. I do this all the time. do not disconnect the cooling fan, just un=plug the a/c clutch if this bothers you.