Roof A/C Fan Modification (continued)

I have elected to make this modification in such a way as to allow me to return to "Fleetwood Operation" at the flick of two switches. ("Fleetwood Operation" meaning that the a/c fan would continue to run until the ambient temperature is 5 degrees below the thermostat temperature). If you do not want the ability to return to "Fleetwood Operation", you can eliminate the two SPST switches below. HOWEVER, if you eliminate the two SPST switches, you will lose the operation of the Low Fan (running just the fan on low speed without using the air conditioner).

You will need the following parts:

I used a Radio Shack Project Enclosure with PC Board, part number 270-283A, cost $3.99. You may also want to get a Terminal Strip to help connect the wires, especially if you get an alternative project enclosure box that does not include a pc board. If you do not install the SPST switches to return to "Fleetwood Operation", you could easily get by without needing a project box as you could just glue the relays to a piece of wood.

Here is a picture of all the parts:


Now, all we have to do is wire up the components and connect to the proper ECC terminals. Here is a schematic for our wiring:


NOTE: GND above refers to coach ground. DO NOT use the Blue pigtail wire for ground.

When the a/c compressor is on, 12v dc is supplied to the relay from the yellow pigtail wire. This energizes the relay and causes the normally open contact to close, completing the circuit for the gray wire of the pigtail. When the compressor turns off, the 12v dc current to the relay is removed, causing the relay contacts to de-energize to the normally closed state that breaks the circuit for the gray wire, turning off the a/c fan. By turning the SPST switch "ON" you can bypass the relay and the fan will now operate as Fleetwood intended.

Now, wire up your parts and insert into your project box. Be sure to solder everything well.

Here is my completed project box, ready for installation. Make sure the four wires for each a/c unit are long enough! The green wire connects to the ECC Module yellow wire, the black wire connects to coach ground and the two red wires connect to each end of the gray wire after it is cut (Note - you will do this twice, once for the front a/c and once for the rear).


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