dash blower motor problems

[viper]

My dash blower fan has 4 speeds and it only works on the #4 high speed setting-settings 1,2,and 3 do nothing. Also the A/C does not cycle on or "load up" when it is turned on. The heater works fine! I'm not sure if it is a low freon or compressor problem? Any suggestions? Thanks

[Don/Lou]

There is a resistor set up on the slow speeds-hi speed is a direct connection to fan
The resistor(s ) are burnt out -need to replace them if seperate from switch or switch if built in
Dont know what chassis you have???

[WindsorDave]

Quote:

Originally Posted by viper My dash blower fan has 4 speeds and it only works on the #4 high speed setting-settings 1,2,and 3 do nothing. Also the A/C does not cycle on or "load up" when it is turned on. The heater works fine! I'm not sure if it is a low freon or compressor problem? Any suggestions? Thanks

Don't know what your set-up is but this is how I fixed my fan-runs-on-hi speed-only-problem.

Dash AC Fan Repair

[wa8yxm]

In addition to the resistor (And the switch) some vehicles (GM does it this way) have a "Low speed" relay. (And a 2nd relay for high speed)

Just so you know.

Trace wires with volt-meter in hand... That's the best way.

[WOODYDEL]

Short video to help you:

http://www.youtube.com/watch?v=2vmfxYg8LoY

This is his website:

http://www.youfixcars.com/blower-motor.html

[viper]

Thanks everyone for your comments and advise. I have a Ford F53 chassis, and from what I'm learning I'm fairly sure I have a Blower Resistor Block failure, so I'll look under the hood and see if I can figure out where Ford put it!