Dash Air Will Not Blow Cold

Wayne M · 01-04-2009, 02:59 PM

Picked up the coach from the repair center just before the holidays and started on our trip. When I picked it up it was cold outside, so I turned the dash heat on. When we departed for our trip we needed air conditioning but the dash would not blow cold no matter what position every thing was in.

Any suggestions?

BigRedLancer · 01-04-2009, 03:09 PM

What year MH do you have? I have a cadillac that needed a recharge after only six years. All I could get is "cool" air. The coolant used in some vehicle ACs, R134A, is prone to leaking out. R134A is being phased out due to toxic manufacturing byproducts and hazards for AC techs.

r4etired · 01-04-2009, 04:02 PM

Check the cable (that selects heat or cool) where it attaches to the damper in front of the heater. Thats what I found when I had your problem.

RCtime · 01-05-2009, 03:42 AM

Wayne, it would help to put the type of rig you have in your post.
Your profile says a destination so, My Journey had the same problem and this may not apply.
Here is what I found.
The vacuum contolled valve that operates the on/off for hot water to enter the heater core was not shutting fully, allowing constant hot water into the core and no cold air when in the AC mode except when in the MAX position.
also mqake sure the vacuum pump that operates this valve is working.
There has been much discussion on this so a search will get you tons of info.
Good luck. Ron

Wayne M · 01-05-2009, 05:00 AM

The information on rig is in my profile, but I'll stick it in here for easier recognition. Thanks.

And thanks for the suggestions. I'll check them out - and since it is under warranty, might just make the dealer deal with it.

Wayne M · 01-15-2009, 12:53 PM

It was the "Expansion Valve."

It has been replaced.

RCtime · 01-15-2009, 02:26 PM

Wayne,
can you explain in more detail. I am very interested.
What and where is the expansion valve.

rvcarpenter · 01-16-2009, 07:35 AM

Yes I would also like to know what the expansion valve is.

Wayne M · 01-19-2009, 07:08 AM

Darn! I wish I could be more specific, but I just held it in my hand for about 20 seconds and handed it back to the part manager. It had 4 ports on it and the stock number according to my receipt is 103930-20-700 (Winnebago). A search on that number on the web will reveal that it goes back quite some time in years for that part number.

Here are a couple URL's the describe an Expeansion Valve

And another definition.

It seems it goes at, or near, the outlet of the condenser.

I hope that helps. The Coach is in storage right now, awaiting my transfer to Freightliner for the 6000 mile check up, and a small system air leak. When I get it back I'll see if I can find that little 1 inch by 4 inch block called the expansion valve and get more details.

Wayne M · 01-30-2009, 07:13 PM

Well, guess I got a new expansion valve for nothing. Took the rig back to the dealer and when I check on it they had replaced the (i think) thermocouple module on the front firewall. They cranked it up for me and it was blowing cold. As soon as I get the part and number I'll post it here.

TXiceman · 01-31-2009, 04:55 AM

Quote:

Originally posted by BigRedLancer:
What year MH do you have? I have a cadillac that needed a recharge after only six years. All I could get is "cool" air. The coolant used in some vehicle ACs, R134A, is prone to leaking out. R134A is being phased out due to toxic manufacturing byproducts and hazards for AC techs.

BigRed, you need to visit THIS website to see the government regs fro the refrigerants. I believe you have R-12 confused with R-134a.

HERE is the MSDS (Material Safety Data Sheet) for R-134a.

At present there is not a new replacement for R-134a and your A/c techs need read up on the refrigerant requirements.

All refrigerants present varying degrees of safety and exposure concerns. All refrigerants leak as well. When R-134a was first used to replace R-12, there were some major issues with the compatibility of O-rings and gaskets. The oil used with R-134a would attack the materials and cause leaks.

The replacement for R-11 (used in large building water chillers) was R-123 and it did cause some serious health concerns. It is pretty much out of use now.

Ken

mikenmo · 02-11-2009, 12:04 PM

Hey Wayne M, we have a 08 Tour 40td and had the same problem, no cold air. we took it to an auth Winny dealer and they found that the thermocouple module on the front fire wall not working. The part was ordered and replaced, it works fine now. It took a while for us to get it done since it required putting it back in the shop. It was a simple part change out but had to be done by an Authorized repair shop for it to be under warranty. Great coach, as we get the bugs worked out....

Wayne M · 02-12-2009, 04:48 AM

Mike,
That is exactly what they found was wrong. Thanks for responding.