I spend about 2 hours this morning replacing the blower motor on a 87 300d,just to find out that nothing is wrong with the old one...ACC seems to work fine,pushing the buttons I can hear the valves working,also I tested the blower regulator behind the brake booster? and got power on the red wire.My questions is,how can I make shure that is the problem,can I bypass that regulator,jump the wires?