Workhorse chassis blower motor

[L D Hobbs]

I have a 2001 Condor on a workhorse chassis and i'm having trouble with the blower motor for the engine a/c.
the a/c blows cold but the blower cuts out and then comes on after a short period.it has 4 speeds and also will not work on high speed.
I have replaced the resistor and the high speed relay and nothing has changed.
I checked the power for the blower motor at the plug with a test light and when I turn the switch to high the test light goes out
the switch it's self checks out good
kinda at a loss at this point
ready for some ideas

[BFlinn181]

When you said you replaced the resistor, was it the full set of resistors for each fan speed? Usually when one of the resistors fail, the fan defaults to full speed on that setting. When the motor cuts out, does it do it suddenly, like power was cut, or can you hear the fan going slower until it stops? If the former, I'd suspect a loose connection, if the latter, I think the motor needs replacing.

[chboone]

Workhorse did not supply the dash AC system except for the compressor and condenser. The Motorhome manufacturer supplied the remainder of the system. Evans Tempcon is a major supplier, you can get schematics and manuals from their web site if that is the system you have.


Evans Tempcon > Troubleshooting, Diagnosis and Repair > Owners > Owner's Manual

[Dsrtrider]

Sounds like it could be a relay or relay connection problem. Also did you check to see if there is any melted connections behind blower switch? Also you could have a blower motor drawing too many amps frying other components.

[chboone]

You say the fan speed checks out ok. Have you actually checked at the switch on high for voltage or loss of with a VOM?