I own a 1994 mustang v6 3.8..the cooling fan is hot wired. it's always on...it has just started to get cold where I live and I have been using the heat. Here is the problem: When I turn on my heat and the car is at idle I have no heat blowing in the car, this is when the temp guage begins to rise making the car overheat, as I start moving and increasing in speed I get heat blowing out of the vents and the temp guage decreases..but as soon as I stop at a light, and give the car no gas, i get cold air blowing out of vents and guage rises. When the car gets into the hot zone coolant starts coming out of the radiator..but when it cools down it stops.....Im thinking this could be because the cooling fan is keeping the motor really cold, on top of the really cold weather, and the thermostat is only opening when the car is accelerating and closes when stopped at light because it's not up too temp..im not really sure what the deal is..im thinking maybe getting a lower temp thermostat for the car because of my lack of a cooling fan that goes on and off automatically.. Any suggestions or possible solutions would be great. thanks!