My 76 vette has had some of the AC components removed (Compressor, condenser, brackets...anyone selling parts I'm interested for the right price). My issue is that the fan will only work on low speed. If I lived in California I wouldn't worry about it too much, but since I live in Washington State, I'll need it to defrost the windows this winter. It has a new switch and if I jump the fan directly to a power source it blows fine. I know there's a low pressure switch somewhere. Do I need to jump the switch? If so, how? Thanks.