I have and 89 GP SE with 49000 miles on it, I have replaced the thermostat and flush the radiator and the temp gauge never gets above 1/3 of the way up. except when its 100 degrees outside and it will eventually heat up and the fan kicks on and everything is dandy. but winter is right around the corner and i don't want to be cold all the time. is it possible that i got a bad thermostat?