Component Testing: Rheostat
Remove rheostat from instrument panel. Connect positive battery voltage to terminal No. 1 at rheostat switch. Connect negative battery voltage to terminal No. 3. Connect test light between terminals No. 2 and 3. SeeFig 1 . Rotate rheostat knob in both directions. Test light should get gradually brighter in one direction and gradually dimmer in opposite direction without flickering. If rheostat does not test as specified, replace rheostat.