...in my jeep, I need that puppy running full blast in the summertime.

I'm encountering a similar problem in my Civic, in reverse. I need a cooling fan to keep my empeg cool in the winter. Running the heat in the car for extended periods of time (30+ minutes) just pushes the empeg's temp too high. The vents run directly behind and above it in the dash.

In the summer, if I either have the windows open or the A/C running, the empeg is happy as a clam. So on/off would be all I'd need.

I've already purchased my fan, and just haven't gotten around to installing it. My recent trip into NH (2 hours total driving time) reminded me that I should hop to it.