One problem related to defogger has been reported for the 2004 Volkswagen Passat. The most recently reported issues are listed below. Please also check out the statistics and reliability analysis of the 2004 Volkswagen Passat based on all problems reported for the 2004 Passat.
My a/c blower motor works when it wants to and most of the time when it's hot it does not blow. The blower motor will start on it's own sometimes driving down the road. Or if I go through a car wash (drying cycle with the blower) it will start up. I had it at 2 vw shops and they could not find the problem.