Last night I had stopped at a friends house and left my car running, when I came out car was overheated. I let it cool off and added some water to get it home. I found that the 20amp fuse blew for the fan. It threw out coolant when it overheated, I refilled the coolant tank and made sure that the fan was working. This morning driving into work I noticed that it was kinda warm air blowing from heater, when I turned fan on high it started to cool down and blow cold air, then a few minutes it would heat up and blow warm air again. Is it possible that it's just air in the system from losing coolant and then adding again?