Only high speed working on my dash blower

Ken & Joyce · 01-09-2007, 01:27 PM

Just for general information. All my dash blower speeds quite working while on a trip except for hi speed. The problem was in the resistor pack located under the hood on the passanger side. These resistors are wire wound which drop the voltage for each speed. There is also a diode in the pack which in my case was defective. The resistor pack is made by Ford. Motorcraft part no. FMC4C2Z19A706AA. It can be purched at a Ford dealership (parts dept) My motor home is a 2003 Workhorse Chevorlet V33

Ken & Joyce · 01-09-2007, 01:27 PM

Just for general information. All my dash blower speeds quite working while on a trip except for hi speed. The problem was in the resistor pack located under the hood on the passanger side. These resistors are wire wound which drop the voltage for each speed. There is also a diode in the pack which in my case was defective. The resistor pack is made by Ford. Motorcraft part no. FMC4C2Z19A706AA. It can be purched at a Ford dealership (parts dept) My motor home is a 2003 Workhorse Chevorlet V33

DonavonP · 01-10-2007, 06:01 AM

Ken, Thanks for the part number, distributor name, and the location. Good info for my black bag.

Art D · 01-10-2007, 09:27 AM

My problem is just the opposite. Works fine on all speeds but high. Blows the fuse on high.
2004 Sightseer 30B

Ken & Joyce · 01-10-2007, 01:19 PM

Good chance that your problem is with the relay. The relay should be under $20.00 in a auto parts store.

Fstop · 01-10-2007, 01:46 PM

In most cases, the relay is by-passed when the switch is turned to the high speed setting.

Mike Grimes · 01-13-2007, 02:33 PM

Ken, just to verify as I had the same problem during recent trip with my Vectra, your chassis is a Chevrolet, but the fan control utlizes a ford resistor pack? Also could you give me a little more information as to where to look.
Thanks
Mike

Pete B · 01-13-2007, 04:37 PM

The same thing happened to me. My Workhorse service center fixed the problem eventhough they claimed that it is rightly a Winnebago problem. It was the diode, but I did not know it was a Ford part.

Ken & Joyce · 01-14-2007, 11:39 AM

Mike, When you are standing in front of your RV with the hood open look for a plug with four wires attached. This will be on the passanger side of RV. The wire colors on my RV is white, orange, green and red. Could be different colors on your RV. Pull the plug from the resistor pack.
Then remove the two screws. One located on each side of the resistor pack and pull the pack straight out. You will see three wire wound resistors (look like small springs. Each one a different size.) Also a small diode. The diode may look ok but be actually bad. Can't tell by looking at it. It can be checked with a continuity tester. To be good you will only get continuity in one direction.

"007" · 01-14-2007, 04:37 PM

Mike Grimes welcome to the forum and the Winnebago forum.

Thanks for joining in enjoy the forums and do post often.