Community Forums

John Stott · 04-17-2012, 09:45 PM

I recently purchased a 2005 34 ft. National Seabreeze on a F53 chassis and find that when on full high speed that the dash blower motor will cycle down (from full high to low speed) after 5 minutes of use. it will then cycle back up up and down again. This happens on both air conditioning and heating but will not happen when medium blower fan speed is selected. What is up? It this a problem (eg rister in the blower fan) or is this normal for the 2004-2005 Ford f53 ?

Thanks, in advance?
John

garym114 · 04-17-2012, 10:02 PM

It is not normal.
Check these dash controls to see if yours is an Evans Tempcon unit and follow the troubleshooting guide. http://www.evanstempcon.com/tsg_hvac.php

rexabbot · 04-18-2012, 07:18 AM

It is either the fan switch it self or the resistor that you would find on the duct going to the fan. High speed runs on a different circut than the other speeds.

John Stott · 04-18-2012, 11:13 PM

Thanks for the good advice guys.

Richard S. · 04-19-2012, 06:12 AM

National RV did use Evan Tempcon

JaMa · 04-21-2012, 08:58 AM

I just got a new to us unit on the Ford chassis and found our dash blower only works on the highest fan setting. Plan on looking into it this weekend. Will see if I can find resistors mentioned in a previous post.

John Stott · 04-21-2012, 11:07 PM

Where "Exactly" is the risister located?. Is it on the blower motor housing ? or is in in-line along the hose" or is it at the dash switch/ Does any know?

rexabbot · 04-25-2012, 06:01 AM

Quote:

Originally Posted by John Stott

Where "Exactly" is the risister located?. Is it on the blower motor housing ? or is in in-line along the hose" or is it at the dash switch/ Does any know?

It is located on the side of the blower box near the fan.

I am in the middle of troubleshooting mine. I felt the resistor when it shut down and it wasn't hot but the fan switch on the controller was. So I believe my issue is the controller unit. Mine has the slider fan switch unit. RV218416 Slide Action Control Panel. This is a very common unit used in many different vehicles. Replacement is almost $500 from Tempcon. But I should be able to find one in a junk yard for $30 or $40.

John Stott · 04-26-2012, 09:51 PM

Thanks. This is VERY helpful.

JaMa · 05-01-2012, 09:03 AM

I have been following your dash fan problem because I also have a speed problem. I tried Evans but after contacting them, it was determined they were not the supplier. It turned out to be Frigette.

http://scsfrigette.com/hvac-systems-...l-vehicles.php

They both use the same Ford control panels so it is not obvious who the supplier is. My problem is the fan will only run at Hi speed. I found the resistor on the front of the heater/air condensor plenum in the engine compartment but is tested OK. I just down loaded the wireing diagram which Frigette sent me and I see a Relay in the circuit which I had no knowledge of. From the testing I have done before getting the diagram I believe the relay will be the problem. The Evans system does not include a relay, at least in the wiring diagram. Now all I have to do is locate the relay.

If you have not solved your problem, I hope the above link will help.