Dash air conditioner

[hawkeye38]

This is a 1999 Winnebago Chieftain 35U on a Ford V10 chassis. My dash air conditioner has decided to direct all air up to the windshield. No cold air comes out of front or bottom vents. I think the control for this is a vacuum operated actuator in the engine compartment. Does the vacuum come directly from the carb or from an accumulator somewhere? I How can I check? Thanks.

[Tom N]

These two diagrams may help you.

-Tom

[Johndale]

First. Thing to look at is the round ball looking thing in engine compartment. That hose will sometimes come off. If that looks good you will see a blue vacuum line on the passenger side in engine compartment. That is your max air door. That hose might look good but it gets little pin holes because were it is installed. What I have done on many that I have found bad is an easy fix. Cut blue line about 6 inches from were it goes into the RV. Now you can put tape over the short end and it should work fine. Then go to any auto parts and replace the bad hose. If blue hose is good with a piece of vacuum line slide blue line in center to splice it back. Or go to harbor freight and buy a vacuum checker and remove the connector and check each line.


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[hawkeye38]

Thanks both of you for the info.The blue line to the air/maxair operator has been repaired but may need more attention. Above that operator is a panel with the thermostat, a junction connector that has several wires going back into the dash area(I think) and another device that looks like an electric operator. I don't see any other vacuum operators. I am afraid they are behind the engine compartment under the dash. I am going to see if I have a good vacuum first. There is a softball size accumulator that has what looks like a 1/4 inch line coming from the engine area and then has a small line going into the dash area. Am I going to have to remove the dashboard to get to the other vacuum operators and switch? How hard is that? Or can I get in there from the engine compartment? I can't find anybody locally that works on motor home dash air conditioners.
Bill W5EC

[Johndale]

On that accumulator it has a check valve built in it so make sure your line in and out is on the correct side. Don't ask me how I know this. 😁


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[hawkeye38]

SUCCESS! The softball size accumulator seems to be for something else-I can't tell. Following the lines back into the engine, one goes up inside the dash and the other drops down beside the engine. In the engine compartment I found several vacuum lines not associated with the a/c but one line from the engine dropped down the passenger side to a box under the plenum area. Further underneath inspection showed that the box was a football size accumulator. While trying to see where some of the lines go, I found that the line coming from the engine connected to a tee from the accumulator but the rubber connector from the hard plastic line to the tee was rotten and had basically disintegrated. It was open ended. I found a 2" piece of rubber fuel line that fit perfectly and that restored the connection. A system check showed the cold air was now coming out of the dash vents and the other functions properly working. All that trouble for a 10 cent piece of rubber hose! The Ford place probably would have charged $200.
Bill W5EC

[rottenkid]

Would this apply to all Winnebago models?

[hawkeye38]

It's not going to apply to all models but there will probably a lot of similarities. My unit is 16 years old, gas, on a Ford chassis. I'm sure technology has made improvements over that many years and each manufacturer will do different things. I have never seen inside a diesel unit, so I can't even imagine how different a rear engine unit would be. On the bright side, automotive a/c is still automotive a/c. There is a lot of help here.
Bill W5EC