Heater, temp gauge erratic

chas35

The temp gauge doesn't move for about 20 minutes after starting and only touches the first line or slightly above. The heater seems to work, although just on the highest blower setting. It only puts out warm air and sporadically goes cold for a few minutes.

From what I've seen so far, I can replace the resistor behind the glove compartment for the blower, right?

The radiator's full to the top, and the reservoir is about 1/4 full when cold.

chas35

Missing thermostat?

Mr_Shiftright

You'll need a lot more diagnosis---first off, to decide whether the air turning cold is because of a blend door being shut, or heater valve turned off by the HVAC module, or if, in fact, you have thermostat issue or air blockage in the cooling system. You may want to scan the HVAC system for codes and see if anything comes up (you'll need the proper type of scanner to do that).