Dash air not blowing cold

[sinjin79]

My dash AC on my 2005 Coachmen Santara MH isn't blowing cold. I took it to a local garage and they say the unit is blowing cold but the air isn't passing through the dash ducts.

I'm assuming there is a main duct that is stuck between the AC unit and the dash or there is a blockage.
Any suggestions?

[bob dirt]

Probably has a vacuum damper that changes air flow direction for heat, a/c, and defrost. Could be bad. Could just need a little nudge. If you have a glove box, it might be behind it. May be accessible front the front hood. Maybe go to a garage that knows what they are doing. Try to keep messing with the controls and go between all of the settings. It might work loose

[Sagecoachdriver]

I had that happen a few times on my old Chevy van, air came out the defrost. As mentioned earlier, it's the vacuum line leaking. The best way to find it is start under the hood and look at all the vacuum hoses around the fan blower and try pushing them in looking for cracks. If that doesn't work, you'll have to remove the engine cover inside and start at the vacuum manifold on top. That's where I found my leaks. Heat from the engine dries out the rubber vacuum tube. Best to replace the hose if you can as cutting off the bad piece and reattaching it will only lead to doing it again at some later date. Don't ask me how I know. Good Luck!

[sinjin79]

Thanks to both of you for the responses. I will try with the easiest first (ducts) and then work my way to the vacuum hoses.

If all else fails I have a service contract that will cover the repairs except for a $99 deductible. The problem there is the local Coachmen dealer is backed up to the end of the month and we are heading south before then.

Adapt and survive.

[pmsherman]

I had a similar problem on my class A Georgetown. The compressor and fan were running but the only place air would go was to the defroster vents. It turned out that the vacuum feed line to the switch that controls all of the air direction handling had fallen apart in the engine compartment. It took 30 seconds to reattach the line after I traced it down.

Phil

[Greydragon]

I have a Georgetown and the dash a/c works fine, but after driving about 6 hours last month, the unit started blowing warm air until it became hot air. The next day it was blowing cold air again. Any ideas? We lost 2 out of three a/c's on that trip. No fun in the sun :-(

[waiter21]

Automotive (and RV) systems are designed so that if they fail, i.e. loose vacuum, they will fail to the defrost mode, i.e. blow air out the defrost vents.

If this is whats happening, you probably have a vacuum line that's cut or disconnected.

As for hot air, Many cars use a "Blend Door" to mix hot and cold air. On my F53, It doesn't have a "blend door" it has a water shutoff valve.

If this valve fails to close, you get hot air. Some of these valves are electric, some are vacuum , and some (mine) are controlled by a cable.

[Greydragon]

How do I check the valve? Where is it located? Thanks

[waiter21]

Look under the hood and find the two coolant heater hoses that go into the heat box (passenger side). If your not sure which two are the heater hoses, with the engine at temperature, run the heater at max temperature with a low fan speed. both hoses will be HOT.


One of those hoses will have a valve in line.

With the engine running and up to operating temperature. Turn the AC on max with the temp set at the coldest.

There shouldn't be any flow in the heater hoses if the valve is closed. Fell the hosses, neither one should be HOT, ALSO, if one is warm or hot, and the other is cold or cooler then you have coolant flowing through the hoses.