Sitorr, the Max is set up like most vehicles where the engine should run at a predetermined temperature for many reasons, not the least being performance and longevity. When the Max is cold, the thermostat is closed so the engine can warm up quicker. At about where the rivet is on the temp gage the thermostat opens. This is the lower temperature in the temp range. The thermostat is the main heat controller and it's degree of opening varies with the temperature of the engine. When the engine temperature goes above the rivet, the thermostat is fully open. The upper temp range is controlled by the temperature sensing unit or 'switch', that some like to call it. About half way between the rivet and the thin red line, this switch turns on the fan to lower the temp. Letting the temp go up to the thin red line is the upper most desirable temperature. If it keeps rising in the red, that's an indication to be aware and NOT let it get into the bold red line. So between the rivet and the thin red line = no sweat. Like so many have done, installing a manual override switch to cool the nerves mostly is a cheap and quick fix. Changing out the sensing unit (switch) to make it run cooler than intended is not a wise decision.
