Precept dash selection failing

[tdbrackett]

Our 2018 Precept 33U is experiencing an unusual dash failure. I can set air to defrost and/or floor, it not dash. When any dash air combination is selected, it still comes out on the floor.
It was working normally at the beginning of our trip, and then suddenly stopped working. After some research, a vacuum issue is described, but has a symptom of only defrosting. The floor shouldn’t be working. Any thoughts or guidance is appreciated. I’d also like to know how much disassembly is required to get under the dash area. I’ve accessed behind the radio, but that doesn’t get you far.

[Rice1951]

Is your coach still under warranty? If so, either contact your dealer or Jayco to get the repair process started. If not, then you can take it wherever you want for repair or attempt it yourself.
I had the same issue with my coach during the first year of use. Worked perfectly and then would only direct air through the defrost vents regardless of which position the selector switch was in. I had it repaired under warranty when I brought it back to Middlebury for a more serious repair issue. According to the completed Factory request service form they replaced a bad control module. Good luck to you.

[hawkster]

Someone on here said there was a vacuum line running to dash control knob near radio. It had become loose causing the problem you describe. I think they had been working on the radio and had the center section pulled out.

[adaigle]

Dis you ever have the problem fixed ? I have the same issue. Thank You

[tdbrackett]

Fortunately I’m still under warranty and it is on the checklist for next weeks appointment.

I’ll let you know how it turns out

[Dacchef30]

Did you ever find out what the problem was? I have a very similar problem. I have learned if air only comes out off defrost on any setting, then it is most likely a vacuum problem. Mine is similar to yours. When set to defrost, air comes out of defrost only. When set it to floor, air only comes out on floor, when set to defrost and floor, air comes out both defrost and floor as it should. But when set to center dash or center dash and floor mixed, it comes out on the floor. I would appreciate any help.

[tdbrackett]

My issue was caused by a mixer (under the dash) getting stuck between output settings.

Originally, they were going to replace but the replacement arrived damaged (missing a few rivets) so they were going to replace again, however this work was being completed the day we arrived to take our coach back and the suppliers were in the midst of supply shortages (Spring 2020) so they fixed the rivets on site and buttoned us up.

It is has been working fine ever since.