My '71 442 has been doing good. Took it on the Hot Rod Power Tour and it did well for 1k miles. Last night I noticed that the heat/a/c fan was not doing right. When stopped, at idle, the fan would not blow at all. When going down the road, the fan operates but not very well. When on the max setting the fan blows normally. What does this sound like the problem is? Fan switch? Relay? Bad fan motor (I replaced it when doing the restoration.) Thanks for any advice.
Mike

 

Sounds like the blower resistor has gone south or is fixing to.

I cannot remember the location of the resistor, but I ~think~ it is inside on the heater box with a 3-4 wire plug going into it.

Can anyone confirm?

When you say "max", do you mean high fan speed? If so, then the motor sounds good...

If not the resistor, possibly the fan switch, but I suspect the resistor.

 

Rob is probably right. The resistor usually goes bad. It sits on the top side of the air plenum in the engine bay. I think it has two small machine screws keeping it on the air plenum and a 3 prong swith. Definitely worth checking out since it is easy to swap out. It is probably pretty cheap too. Hopefully you could find it at your local auto parts store.

 

There may also be a small ambient temperature switch on the plenum also - it has only two wires and is NOT what you are looking for. This simply kills the compressor when outside temps are below 40* or so. It will have a brown and green wire on it.

 

If the resistor checks OK trace the wiring from the relay I have repaired alot of these as the get hot at the connector

 

Thanks fellows. I am going to get a new relay. I suspect that is the problem.
Mike