I have a '94 Astro bought used a year ago. Took it on a 3000 mile round trip last summer with no problem. Now has 45K. A week ago suddenly there was a smell (intermittent) coming through the vents from the engine when the fan is in the "VENT" position. Does NOT happen with AC on. Oil, trans, coolant levels all OK. Thought maybe it was a refrigerant leak on the engine. Took it to a Chevy dealer, who could not duplicate the condition. (Told ya it was intermittent.) NOW it appears that maybe the smell wasn't coming through the vents (though I could have sworn it was), because I caught a little wisp of smoke coming from the fan switch. Dealer's electrical expert says nothing to worry about, could just be dust on the switch. This is a reputable dealership that says they try to avoid unnecessary parts replacement & expenses. I'd like to resolve this before taking another long trip next month and am strongly leaning toward replacing the switch, anyway. Feedback? Similar experiences?