Dash air doesn't work

...BTW, it is a Evans part...

Evans Tempcon, I think it's called. There also was SCS/Frigette, but I believe they went out of business.

Fortunately your friend has a Winnebago product, and that company is very good about parts and the related customer service for their motorized products.

Don't rule out those vacuum leaks, as so many have said. Somewhere, there is a Check Valve, and a Vacuum Reserve Tank. Trace all the way from Engine to Check Valve to Tank then on to the Controls and the Servos. If you suspect a hose or plastic line, replace it. You don't have to follow its path, just get the vacuum from its source to where it needs to be.

http://www.evanstempcon.com/serviceparts.php

Click this link. She has a Evans Tempcon system. ALL Class A motorhomes regardless of chassis have aftermarket controls and evaporators. It is extremely rare for the Dash Control to cause vacuum problems or have a leak. You will see 2 controls like hers and odds are she has the cable LESS control. Cable controls went out of favor almost 20 years ago. This Part is extremely EASY for any competent shop to get. After 3 tries I would NOT be comfortable with their ability to diagnosis and even get the right part. Most of the time, the Shop blames the supplier when it is the fault of the Shop that fails to get the right part. Doug

I had a vacuum failure in my '90 Bounder and the control was from a Dodge Dart. I think that Winnie is a little more on top of things than that so here's how to start;

Go to the Winnebago.Com site and download the parts catalog for that model.

Make sure the part is available, it probably is from Lichtsinn. Don't buy it yet because you probably don't need it, it's just for knowledge in case it is bad. Knowing you can mess something up and have access to a replacement is comforting.

Buy a Mighty-Vac hand vacuum tool, or one from HFT.

Remove the vacuum lines one at a time from the control, using the M-V check for leaks and return good lines to the controls and replace any bad one with black rubber hose as noted above.. I'll bet you find the leak or bad activator motor real fast with the M-V.

I would take a couple pictures and label any lines you replace with the color of the original line or the vacuum motor it goes to.

Photographing the back of the control with all wires, cables and vacuum lines and labeling any lines replaced with a black hose is just a precaution for trouble shooting in the future.

When I had a failure with the Bounder, the workers(not really techs) never checked for leaks. When I got it home I went to an Auto AC shop and picked the owners mind. He said it was simple and it was. You just have to have faith in yourself. If your friend doesn't want to do it himself, go to any GOOD, REPUTABLE, Auto AC shop. They really do know what to do, they just charge +/- $125.00 per hour.

I recently had a similar problem with a 2007 Itasca Suncruiser 35L on the Workhorse chassis. I thought I carefully diagnosed the vacuum leak and improper operation to the vacuum control and ordered a replacement. After install, the problem persisted. Further diagnosis found a vacuum line that had deteriorated with pin holes in it. It was the vacuum line under the front hood that goes to the recirculation servo that is on the passenger lower side of the heater box. This line Tees under the dash. One part goes to the recirculation servo and the other one goes to the valve in the heater water hose. I eliminated the Tee under the dash with a piece of 1/8" rubber vacuum tubing and then put a Tee in the line under the hood to the heater water valve and added a new 1/8" rubber vacuum hose on to the recirculation servo. This eliminated the source of the vacuum leak for my problem.

Make sure you carefully check all the plastic vacuum lines for leaks. They can be replaced by 1/8" rubber vacuum hose that you can buy at any auto parts store. My plastic tubing under the front hood had pin holes in it from sun damage entering through the front end of the coach.

The vacuum control can be bought here:
Lichtsinn Motors
505 Highway 9 East
Forest City, IA 50436

641-585-3213
800-343-6255

You will need the Winnebago serial number for the coach. I think I paid about $60 for the vacuum control. BTW, it is a Evans part.

Again, really check the vacuum tubing for leaks. It is a lot cheaper than the vacuum control. Good luck-- Mick

First question is who made the a/c unit. Denso made many of them. See pvt message about a manual. That brand is quite common and parts are easily available.

What's the needed part number?

Bill