[jkeyzer]

I would take it apart again and make sure that if you supply 12V to the fan directly it still works. It is possible that when you installed the fan one of the wires to the motor broke loose. The light inside the car is actually separate from the wiring that goes to the fan and is triggered by a different set of contacts from what I remember. It is possible to trace the wiring for the motor such that when you pull off the big connector to the housing you can use a multimeter to look for 12V for each speed setting.

Good luck.

As a side note, does anyone know what the ~3" dia. round hole in the trunk next to the drainage hose for the fresh air plenum is for? I have always wondered - does it have to do with the gas fired heater option?