I posted this question some time back and no one could help me. I had a dying blower motor, so I replaced it. When I installed the new one it took right off with the heater/ac off (0 position) and the key out of the ignition. The only way I could get it to turn off was to either pull the fuse from under the hood or unplug the harness from the blower. I ended up installing a toggle switch into the blower wiring harness so I could have heat in the winter(only high speed, but better than nothing). So I'm ready to try and tackle this problem again. Does anyone have any idea what would cause this to happen? I replaced the part that controls the speed but no luck. Please help.