MY TRUCK DOESN\'T WARM UP My truck never warms up, so the heater doesn't work. This makes for a long, cold ride to work every morning. Is there a way to atleast get some heat out of the thing? I put the equivelant of a two core radiator in over the summer, but it didn't warm up very well before that either. I don't think the heater core is bad, because the heater works really well in the summer, when I don't need it. Im going to try a different thermostat, but I don't think its going to make a difference. Is there anything I can do? Is it safe to cover some of the radiator? Any suggestions would help. THANKS!!!