Heater fan

[frankogrly]

My heater fan works on all but the third speed. What is possibility the switch is bad and not the resistor block? The last time the resistor block was bad I thought the fan only worked on the low and high speed.

 

Frank O

01 Endeavor

[philcarrell]

I think resistor block

 

[Tundratech]

Resistor block, that is what changes the speeds when selected

 

[Harvey Babb]

What chassis do you have? The heater/defroster equipment is generally supplied by the chassis manufacturer and not by Monaco.

In general vehicle heater fans work as below. Without the diagram for your particular rig I can't say this is 100% accurate, but;

The resistor block is used to SLOW the motor only. For all but the highest speed the motor power goes through the selector switch to terminals on the resistor block, and from the resistor block to the motor.

The highest speed is usually not fed from the selector switch because of the amount of current required. Instead, selecting the highest fan speed energizes a relay that feeds power directly to the motor. This direct fan circuit will normally have a dedicated fuse or circuit breaker.

If only the highest speed is not working, look for a blown fuse or bad relay. If the highest speed works but any of the slower speeds do not work suspect a bad resistor block or a bad selector switch. If the fan doesn't work at all suspect a bad selector switch or a (lower value) fuse in the selector switch circuit.

 

[CTerry]

I have a 2003 Beaver built in 2002. The blower motor for the AC/Heat will only run on 3rd and 4th speed. Previous posts have directed me to the resistor block. My dash area is different than the same year Monacoes. The fan motor is not accessable from the front of the firewall through the area where the generator is. The motor is buried under the console at the front of the coach. I can see it and just barely feel it but can not figure out how to get to it. Haven't been able to locate the resistor block at all. Has anyone with an older Beaver addressed this problem. Any help would be appreciated.