Regarding the HVAC blower, heater fan, vent, AC box blower. Instead of the stock "toaster" mechanism (coil resistor box mounted in the front scuttle tray) that controls the three blower speeds, could a PWM control unit be used to adjust the blower speed? This would be replacing the existing control lever/switch and resistor box. The PWM control has simple connections; 12V in, and +/- feed wires out to the blower motor. They are a small package with a remotely mounted rotary control knob. Rated for 20 to 40 amps (depending on the unit chosen) for 12V use, they can be found very inexpensively online. Here is a pic of just one of many to choose from: I am planning to replace my AC heater box controls to eliminate the vacuum operated system. So the dash will be modified to install manual levers for the air flow 'flapper' doors and heater valve (also being replaced with a VW item). That makes it a good time to also replace the blower speed control to a rotary knob. In addition to making the non-vacuum conversion a little easier, it also eliminates that 'hot box' thing in the scuttle - which I do not care for. I considered utilizing a electronic control from a newer vehicle but there are just too many choices to know which is best. I guess one added benefit to using the PWM control is the blower will then be infinite speed instead of three. I also think the small rotary knob will look a bit cleaner on the new custom dash (the gauge cluster is being replaced with aftermarket dials). Any info on this from all of our electronic wiz kids? Thanks.