I remember seeing this being done once upon a time and it was summer of course when I never use the defrost. Now that winter has hit, and I hate using A/C all the time. Not even sure why A/C would be installed on a convertible imo. But anyways, any help would be greatly appreciated. Oh, it's a 98 Spyder GS. Nothing fancy. Just good looking.

 

The reason the a/c comes on is because it dries the air in the cabin just like it does during the summer time. Your windows fog up because there is enough water in the air to condense onto the windows....thus, the reason the a/c comes on. You shouldn't have defrost on all the time, only upon getting into the car and after the windows have cleared up. If you have it on while driving because the windows keep fogging up, then you don't have a tight seal between you and the outside or there is water inside that is evaporating and then condensing onto the glass.

 

I guess to clarify a bit, I live in the Rocky Mtn region. Elevation where I live is 7300'. Annual avg precipitation is less than 14". It is an arid area, Humidities reach high 30's in the spring and fall. What I would like to do if possible, is make it so I can run the A/C for a few minutes, then switch it off. The musty smell that happens in vehicles in humid areas does not happen where I live. We don't suffer from vehicle rust. A car can sit for 10 years and not be reclaimed by mother nature. I don't need A/C running while the defroster is running, which can be an entire trip. Sub-zero temps can be killer on any windshield. So I guess before I remove any wiring and whatnot to power the A/C, I thought I would see if it can be solved a lil simpler.