There is a small rocker switch over the driver's door labeled "AUTO Heat" and a larger toggle switch on the dash labeled "AUX Heat". I believe that the AUX heat switch turns on the fans under the couch and under the closet floor. These fans also appear to have their source of heat coming from the engine.

I have three questions:
1. What is AUTO Heat?
2. How do I get the AUX heat to function (i.e. turn on the water flow)?
3. Do either of these have anything to do with the dash heat?

Hi Lance,

In our 92 Breakaway we have a 2-position AUX heat button on the dash and use it frequently. On our bus the heat comes from two heat vents in the bedroom which are independent from the regular "house heating system". The heat appears to come from the engine but I have never explored it because all we do is flip the AUX heat switch and heat appears. It does a very good job of heating the coach while we travel.

I have no idea what the AUTO heat switch is over the drivers door but in our coach we have a switch with a red light over the driver's side window which is the switch for an engine oil pre-heater.

Our mechanic also told us that there is a water shutoff valve somewhere in the rear of the coach which controls the flow of hot water to the dash heater and should be shut-off in the summer when using the dash air as it reduces the cooling power of the dash AC. I remember seeing a turn-off valve under the coach, about three feet forward of the engine on the drivers side. There is also a shutoff in the front of the coach. He said to leave that one alone.

Hope this helps.

Carl Feren

Trace the hoses first; on mine the aft valves shut off engine heat to the HW tank. The valves at the heater cores are a drain and a bleeder, and should be left closed for normal operation.

If you have the typical Chrysler dash HVAC, heat to the heater core (and that what reheats A/C air if it's too cold) is controlled by a valve operated by the heat selector. If it leaks, replace (easy job). On mine, the linkage was out of adjustment and the dash end of the "choke cable" had come loose.

I do not have the rear heater in my Breakaway but the connections are there and I could put the radiator with fan in easily.

The dash air on mine has a bypass style of heater control and when off, there is no heat in the dash air radiator, I don't like to shut the main valve off at the engine in case I need the extra cooling that I can get by turning on the dash heat.

I have re-plumbed the entire heater hose routing with new hoses, mine had several areas where the hoses were abraded and others where there was evidence of pending hose failure.

The aux heat will work when you run your dash heat to heat the rear of your coach. The toggle switch overhead of the driver's seat will turn on a 120volt plug in your engine compartment that your block heater plugs into. That way you don't have to go outside in the cold morning to plug in the engine. Just throw that switch go make the coffee and breakfast and let that engine get ready to go.
Used both these options often on the drive from the cold north to Arizona last week.
Don

The switch over the driver with the red light is the block heater. It powers a heating element that is mounted to extend into the water jacket of the engine. It heats the coolant to assist in cold weather starting. The AUX turns on the fans to the rear compartment heater that is under the stack of drawers at the bedroom entrance. A third one, over the entry door (on front entry coaches) energizes the compartment heaters that feed under the coach. A fan and heating element is mounted in the forward compartment where your potable water tank is located. It prevents freezing of the tank and feeds warm air into the storage bays through small ducts. It has a thermostat that is adjustable to regulate when it comes on - usually somewhere near 40 degrees is recommended.

Thanks to all for there input. When I get daring enough I will experiment with the valves I have located on the underside of the chassis. Unfortunately my water heater had been replaced and the new one does not have the option to hook up the heater hoses. The hoses are there they have just been connected together for now. If I ever replace the water heater I will re-establish the connections.