2006 bmw 330i heating problem dont come on even when a/c on''' i replace the original with after market it work for 2 days, then stop blowin again i replace the after market with another it work for a few minutes the fittin on the top hose brocked n i replace it with another but fan dont come on even with the ac on . how can i check the fan out of the car n check power on the plug.. thk you n will apprechiate your help