Fan Problems

redvettemike · June 17th, 2009, 04:30 AM

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

Lady72nRob71 · June 17th, 2009, 06:27 AM

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.

Olds64 · June 17th, 2009, 06:49 AM

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.

Lady72nRob71 · June 17th, 2009, 07:43 AM

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.

ozoneblue · June 17th, 2009, 09:00 AM

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

redvettemike · June 18th, 2009, 03:38 AM

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

June 17th, 2009, 04:30 AM	#1 (permalink)
redvettemike Registered User Join Date: May 2009 Posts: 71	Fan Problems 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

June 17th, 2009, 06:27 AM	#2 (permalink)
Lady72nRob71 Moderator Join Date: Feb 2008 Location: Plano, TX Posts: 1,916	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 Young 1972 Cutlass Supreme Convertible (442 clone) -"Lady" (My mistress...) http://www.flickr.com/photos/robsalbum/sets/ 1986 Cutlass Supreme Coupe - "Pristine" 1978 Ford (Old Faithful) a.k.a. "the Tramp" 1997 Cadillac STS (for sale - too many cars!) 1999 Harley Davidson Sportster - "the Freedom Machine"

June 17th, 2009, 06:49 AM	#3 (permalink)
Olds64 Landyacht Club President Join Date: Jul 2007 Location: Lawton, OK Posts: 4,286	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. __________________ Ferris, my father loves this car more than life itself... Apparently, you don't understand! Ferris, he never drives it! He just rubs it with a diaper! Cameron Frye Ferris Bueller's Day Off 1986

June 17th, 2009, 07:43 AM	#4 (permalink)
Lady72nRob71 Moderator Join Date: Feb 2008 Location: Plano, TX Posts: 1,916	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. __________________ -Rob Young 1972 Cutlass Supreme Convertible (442 clone) -"Lady" (My mistress...) http://www.flickr.com/photos/robsalbum/sets/ 1986 Cutlass Supreme Coupe - "Pristine" 1978 Ford (Old Faithful) a.k.a. "the Tramp" 1997 Cadillac STS (for sale - too many cars!) 1999 Harley Davidson Sportster - "the Freedom Machine"

June 17th, 2009, 09:00 AM	#5 (permalink)
ozoneblue Registered User Join Date: Jun 2006 Posts: 503	If the resistor checks OK trace the wiring from the relay I have repaired alot of these as the get hot at the connector __________________ OzoneBlue project cars for sale

June 18th, 2009, 03:38 AM	#6 (permalink)
redvettemike Registered User Join Date: May 2009 Posts: 71	Thanks fellows. I am going to get a new relay. I suspect that is the problem. Mike

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