Heater A/C Fan Speed Only Has High Speed

[OT-RoadAgain]

I'm posting this in case it might be of help to someone else. The coach is a 2010 Itasca Ellipse 42AD. Problem was the dash fan would only work on high speed. The fan would not operate when the switch was turned to either low, medium or medium-high speeds. This problem occurred twice before over the coach's lifetime but was repaired both times under an extended warranty. The warranty expired, so now it was my problem to fix.

There are many postings about the resistor set causing this problem. If the fan runs but only at high speed, the resistor set is probably the culprit. This resistor set is what is used to reduce voltages to the blower motor thus providing the speeds other than full high. The resistor set contains a thermistor (fuse that opens when the resistor set gets too hot to prevent a fire) and if it pops, the fan will not operate at the lower speeds.

I removed the resistor set and checked the thermistor. It was open. I ordered the resistor set from Amazon (for this coach the part number is Winnebago Part Number 103930-01-710 and cost $12.25 plus $4.33 shipping https://www.amazon.com/gp/product/B0...?ie=UTF8&psc=1 ) and installed it. This did not fix the problem even though the resistor set was bad.

There is a blower fan relay in the speed control circuit. I removed the relay and cleaned the corroded contacts and that plus the new resistor set fixed the problem. However, the next time I started the coach the lower blower fan speeds were not working again. At O'Reilly Auto Parts they found the 5-pin 30 amp relay under a Freightliner listing. The new $14 relay did the trick.

In hindsight, the relay was probably what caused the initial problem. There would be times when the fan's lower speeds would work and others when they would stop working; even while driving. The relay's switch contacts can get burned over time causing intermittent problems until it finally fails completely. Fortunately for me, the speed control switch on the dash was not bad because, on this coach, it would be a bear to get to. This setup is probably fairly common across coaches, at least in this era. It appears to me the lower-speeds control circuit includes a circuit breaker, relay, resistor set, a fan speed control switch on the dash, and the blower motor.

On this coach, the resistor set and relay are both mounted on the front end of the coach to the right of the windshield washer bottle; resistor on the left and relay on the right.

[Ray,IN]

Thanks for passing the information along to help others.

[dlboarman]

Same problem, different location. This might help other Winnebago owners.

My 2001 Winnebago Journey DL A/C fan quit working on the lowest setting. The medium and high speed work fine. IVR2 pointed to the fan switch or the resistor for the fan speed. I first replaced the switch (easiest) and got the same results, no low speed. This put me searching for the location of the resistor. It was not easy to find. Again, thanks to IRV2 forums. I found it in the compartment where the Onan Generator rides. This is the hood like apparatus on the front of the motorhome. Once this hood is raised the resistor is very far to the left (passenger side) of the motorhome. I could just barely see it and barely reach it. A “shorty” Philips screw driver was needed to pull the old unit out. I tried replacing it but no local auto shop could find one like it. I finally cleaned up the connections (very rusty) and put electrical grease on it and cleaned up the connector and greased it too. When I got them back in, the fan now works on all three speeds. I would guess that over the years the water spray rusted the connections to the point they failed.

Here are pictures of the location and the resistor.



This is the A/C unit under the “hood” of the MH, way to the left is the resistor.



The resistor. If you look closely, you can see part of the connector is melted, at the top. This device is within the air flow part of the A/C and heater unit. The actual resistors are sometimes called “toaster” coils and they do get hot!







This is how rusted the connectors were! I did clean them up and made it work.

[Ray,IN]

Great information men, thank you for the pictures and explanation! I'll get to work on mine this coming week-when it cools down into the 80's. This weekend is high 90's W/ mid 70's humidity. The MH parked in a metal garage makes it hotter and stuffy-er.