Might be the fan motor, too. Try the old trick of tapping on the fan motor case when it stops.

Hey Martin, check and see if you have any exposed wires. Almost sounds like ice may be melting and shorting something out. I know when we were 20 below, my nice dark blue car would still melt the ice on it due to sunlight, and I had water freeze up in some wierd spots later...

that definatly sounds like bad motor bearrings to me! yes definatly try the tappin on the with a screwdriver next time it stops. always did the trick for me in the 90.