When my car is in park and idle it'll kick heat, but when I take it out on the high way the temp gage goes completely cold and starts to blow cold air. If I drive it that way for awhile it'll eventually over heat. First off sorry, I have a Lincoln ls 2004 v8 premium sport I believe. I've check the fluid. I've bled the system a million times, taping on the metal part of the dccv housing will engage a fan when it's up to temp. This summer I took it off and cleaned it cuz I didn't have ac. That worked! I also was messing with my after market system recently and had blown a fuse. Wondering if I maybe screwed up another one or a relay possibly too?