Cab ac in class C

[Sshlinda]

Our AC is not blowing air from the dash. It is blowing through defrost and floor area. What could be wrong. It is a forest river sun seeker 2012 Class C 31.5ft with 13,000 miles.

[grumpy0374]

You have a leak in a vacume line somewhere in the ac system. The defrost is the default where air will be diverted when there is a leak.
There are plastic vacume lines under/behind dash and in engine compartment.
The only ones that are readily accessable are located on the passenger side footwell area. If you can look up under the dash to the far right next to and up from the plastic kick panel you'll see a few plastic vacume lines. If your lucky, it will be one of these lines that has a crack or has come loose. Lucky because these are the easy ones to get too. Rest require partial dash removal, removing dog house, removing battery to access firewall to trace lines, ect. It could also be a crack or damaged plastic fitting that the vacume line attaches too that connects the line to the engine or the ac system. Can be a real bit-h to find.
Had the same problem last May on the road. Luckly found a crack in a line where I advised you too look first. Local auto parts store I found (Auto Zone) had a small vacume line repair kit, a few bucks, that had several pieces of thick wall rubber tubing to act as a splice. Different diameter pieces. Cut damaged piece out and spliced it togather. Hit the road and as soon as air started into system, it blew normally.
Grumpy

[Total Loss]

Ford's still have vacuum operated blend doors?
Wow- I just looked it up- my Chevy does also.

[grumpy0374]

Yup, still using 1960's technology. And, they can be a pain to trace down.
When there is a leak in a line, the blend door/s remain closed and any air is automatically diverted to the defrost vents. At least on the Fords. Not 100% sure about Chebbies.
Grumpy

[s1njin]

Ford also uses a vacuum system to engage the 4wd in their F150. Search IWE failure and you'll get a lot of reading.

Essentially the hubs try to engage on their own due to vacuum loss - which makes a grinding noise in low vac loss cases, or makes it sound like somebody through a bucket of bolts in a blender when it ends up being a steep drop in vacuum pressure.

Happened 2x to my F150. Dumped it at 14k miles. Didn't need it anymore anyway since we bought the motorhome.

[Kevin & Judy]

That would be a Ford problem not Forest River.

[Duckogram]

Originally Posted by Kevin & Judy

That would be a Ford problem not Forest River.

No, thats a sshlinda problem because its a 2012.

[A32Deuce]

Originally Posted by Duckogram

No, thats a sshlinda problem because its a 2012.

You can buy a repair manual for an E350/E450. I did and it helps with the chassis/ Ford.

[A32Deuce]

You might be able to borrow a smoke machine and find the leak that way.

[HerveVR]

Sshlinda,

When the A/C is malfunctionning out the front dash, while on the road, you can run your generator and get the «house A/C» cooling the place.

But, get sure not to drop under 1/4 fuel tank.

[Total Loss]

Originally Posted by grumpy0374

Yup, still using 1960's technology. And, they can be a pain to trace down.

Grumpy

Sometimes old school is the best school.
Waaaaaaaaay too many electronics and actuators to fail in new tech. I see it daily.

[grumpy0374]

Originally Posted by Total Loss

Sometimes old school is the best school.
Waaaaaaaaay too many electronics and actuators to fail in new tech. I see it daily.

I do agree that old school is sometimes the best way to go.
And, I believe using vacume to operate the doors on an ac/heat system is perfectly OK.
Just wish, that with all the new synthetic materials available, they would come up with something better than hard plastic vacume lines. They can crack, split, break, ect.
A few bucks I would gladly pay for some small diameter re-enforced synthetic hose that would last.
Grumpy

[Total Loss]

Originally Posted by grumpy0374

And, I believe using vacume to operate the doors on an ac/heat system is perfectly OK.

Grumpy

They are using them on fuel lines now...near heat sources.


Sorry to hijack the thread.