AC/DEFROST Fan not working

[workinwood]

Hi all,

I am very new to this RVing, just got a 96 Class C, 30ft Minnie Winnie MH on the Ford chasis. Has the 460 motor.- My problem is the cab fan for AC//defrot, heaterdoes not work. I got all the manuals for the coach none for the chasis. Was able to get list of labels for fuse box it stated its is a 30 fuse.. Check fuse looked good, but since II was there I went ahead an replaced it. still does not work. On the left side of steering wheel on dash there is a coach fan knob. And it works great. Any suggestion. Thank you in advance :
Dave

[Bo Walker]

Sometimes the switch itself goes bad. See if it will work on any speed. Sometimes the motorhome heater/AC high speed will not work. But, other speeds will. My 03 Silverado heater/AC fan just recently stopped working on high.

[workinwood]

Bo

I have no fan at any speed, thanks for the help.

[skigramp]

You can see whether the switch is defecting by making a small jumper wire ... and jumper between the input and any of the outputs ... if the fan starts then you have a faulty switch ... if not then it is either the wiring between the switch and the fan ... or the fan itself

[Chief]

Ford products usually use a resistive pack on their AC units that controls fan speed. When the resistive pack goes there can be varying symptoms from "no fan" to the fan running on high speed only.

Check for a wiring harness running to the Heater/AC plenum, probably accessible from the engine compartment. Should be a couple of screws holding it in the plenum and may be somewhat difficult to remove because of space limitations. Remove the resistor pack, test and replace if necessary.

Sorry I can't be more specific. Maybe if you checked a chiltons or other automotive manual or one of the online parts suppliers like autozone for your engine year, they may have a diagram of the AC system and will point out the resistor pack.

Let us know the outcome when you finally get it diagnosed..

[workinwood]

Skigramp and chief
Thank you for the suggestion I will try them and get back to you. Living in the pacific Northwest under the Olympic mountains we average well over one hundred inches of rain yearly. So when it quits and I am not at work I will try suggestions