Knob on the right is a throttle hand control for use off road when the going is slow & bouncy. Keeps you from bouncing your foot up & down on accelerator pedal & 'jerking' forward. Push accelerator pedal down to get desired revs, pull out knob & turn to lock it. You can then take foot of accelerator & maintain revs. It's a good idea that used to be common, but seems to be missing from many modern 4wds. Dunno what RR Heater switch does, don't have one in my car.