So i went out to warm up my car this morning, came back to the car about 7mins. later and i turned the heater on and it work for about 3-4 seconds, then it just went dead. I tried the A/C and nothing either, so then i figured maybe a relay or a fuse, then on my way to work i tried it again and it worked, but it seems that it only works when the car is moving, cuz every time i came to a complete stop the heater just went dead (except when i got to work 30mins later and i was parking it).
Could it be a bad unit? relay? or fuse?
anyone ever had this problem?
thanx for any suggestions.

 

I would suspect a loose connection or ground somewhere. I would probably start there.