Dash Air on Astoria (Freightliner) inop

[DiamondDan]

The dash air suddenly blows outside-temp air. I can't hear any compressor engaging when I select Air (or MAX Air), so I'm wondering where the compressor is and if it is fused, where is the fuse (eg what's it labeled?)
Thanks in advance for any assistance.

[powerboatr]

if your in the drivers seat...you will never hear the a/c clutch engaging
the fuses are in the bay under the drivers seat window

if fuses are good, you need gauges hooked up to verify system pressures

there are several safeties
low pressure switch prevents a/c clutch from engaging

its a LONG run from the rear up to the front
was it working fine then quit suddenly
does the condenser fan run on the coil outside under the passenger side front end

[doc]

(Hope I understand what you are saying) Dan, it may be the little vacuum pump on the front fire wall has failed. This controls all the control function of the ac/vent system. If it goes out, I think it defaults to ouside air. Looking under the hood, it should be on the drivers side and there is a vacuum line or two connected to it. Mine hung up a couple of times and I had to unplug and reconnect it after leaving it disconnected for a while. After a while - and some serious heat - I reconnected it and it worked again. This has happened twice. It may be as simple as a vacuum control hose or power to it.

[DiamondDan]

Quote:

Originally Posted by doc (Hope I understand what you are saying) Dan, it may be the little vacuum pump on the front fire wall has failed. This controls all the control function of the ac/vent system. If it goes out, I think it defaults to ouside air. Looking under the hood, it should be on the drivers side and there is a vacuum line or two connected to it. Mine hung up a couple of times and I had to unplug and reconnect it after leaving it disconnected for a while. After a while - and some serious heat - I reconnected it and it worked again. This has happened twice. It may be as simple as a vacuum control hose or power to it.

That sounds like it might be my problem. Is this vacuum pump on the inside of the coach side of the firewall or outside the coach w/ the generator?
Thanks.

[DiamondDan]

Quote:

Originally Posted by doc *snip* Looking under the hood, it should be on the drivers side and there is a vacuum line or two connected to it.*snip*.

D'oh! Reading is fundamental! I'll look in the AM.

[DiamondDan]

Quote:

Originally Posted by powerboatr if your in the drivers seat...you will never hear the a/c clutch engaging the fuses are in the bay under the drivers seat window if fuses are good, you need gauges hooked up to verify system pressures there are several safeties low pressure switch prevents a/c clutch from engaging its a LONG run from the rear up to the front was it working fine then quit suddenly does the condenser fan run on the coil outside under the passenger side front end

The condenser fan is not running.
The fuse in the fuse panel is hard to check as it cannot be seen through. however, when pulled, the blower fan stops, so it appears to be something other than the fuse.

regarding the vacuum switch for the a/c and heat, those seem to be working normally - i can direct air to floor, defrost, and dash.

So, I'm at a dead end now, and I guess the dealer's service dept will have to look at it. now... which dealer - freightliner or damon? freightliner puts the a/c compressor on the chassis, and damon does all the dash air plumbing.

[doc]

I might let Freightliner look , or at least give them a call and tell you who it should go to. Might be a compressor failure to an in-line fuse failure. Don't you just hate these kinds of problems that are not clear cut.

[powerboatr]

when we had the a/c issue last year because a compressor line failed..
freightliner said their responsibility ended at the engine as damon the up fitter did the compressor and all lines, including the dash components

its an easy check with them if they have your vin

[rvtips]

You don't have to go to a moho replace place,just look for a good A/C repair shop.The sys is just like a car with longer lines.

Quote:

Originally Posted by DiamondDan The condenser fan is not running. The fuse in the fuse panel is hard to check as it cannot be seen through. however, when pulled, the blower fan stops, so it appears to be something other than the fuse. regarding the vacuum switch for the a/c and heat, those seem to be working normally - i can direct air to floor, defrost, and dash. So, I'm at a dead end now, and I guess the dealer's service dept will have to look at it. now... which dealer - freightliner or damon? freightliner puts the a/c compressor on the chassis, and damon does all the dash air plumbing.

[DiamondDan]

fixed. Freightliner fixed one small leak and recharged. I hope it's the only leak. ~$500 into the RV repair budget....