Dash A/C on Land Yacht

[Paul Dobbin]

The last time I drove our Land Yacht diesel pusher, the dash A/C
was a little weak. I read in the previous owners notes that he had it
converted to 134 a few years ago. It occured to me that with the
engine in the rear, I have no idea where the schrader valves to charge
the A/C system are.
Does anyone with a diesel pusher know?

[phred]

Paul;

I have a 95 Land Yacht diesel pusher. Mine came from the factory with 134a, so I assume your motorhome is an earlier version diesel pusher. With that said, my 134a connections are in the front, accessed through the small front hood and then look left. On the opposite side of the "firewall" in front of the passenger feet. Take off the front hood to allow easier access when working. One fitting is just coming out of the heater core box and one connection is higher up and more toward the middle of the coach. Check to make sure you have the newer 134a fittings that snap on like air pressure disconnects at a garage. If you have the screw-on fittings of the older R-=12 refrigerant, you will need those end connectors when servicing the AC. Adding freon 134a is touchy. It is easy to get in too much and the results will be warm when you want cold in the face. Depending on ambient temperature, you may need to put a shop fan in front of the condenser which is located at an angle to road air, down by the front axle. Without the fan, sometimes the unit will not suck in the 134a.

When you are finished I recommend wrapping a shop rag around the high and low fittings as you disconnect them. At least it has been my experience that the snap-on ones blow a lot of oil around the compartment. If you have R-12 screw-on ones, you may not experience that.

The relay that turns on the motorhome condenser fan is high center in that front compartment. It can be pulled and jumped to avoid using the shop fan, but you have to know what you are doing.

Fred

[Paul Dobbin]

Thanks Fred,
Now I'll have a strarting place to see whay I lost my cold A/C.
Just had all the windows tinted, including the windshield. I Florida
that is the best A/C saver thaere is. You are right, this is a 1994
and I have no idea if it came with R-12 or 134a but notes say it was
"converted". I've had real good luck with 134a at about an 80-85%
charge cooling as well as anyhting else. I guess it was questionable
in the beginnnig, but I like it. I used it in my street rod too.
Paul

[Nye Thatcher]

It is critical to add the right amount. If you call airstream they will give you that infomation. The charging connections will tell you if the system is modified, large fittings=134a You must evacuate the system before charging. I installed a manual switch on the evaporater without disturbing the system that is in place. This is easy to do. I switch it on with the A/C. This improved the cooling. CHECK FOR LEAKS the system should not need freeon, unless it has a LEAK. Good luck, Nye

[phred]

[QUOTE=Nye Thatcher]You must evacuate the system before charging. I installed a manual switch on the evaporater without disturbing the system that is in place. This is easy to do. I switch it on with the A/C. This improved the cooling.

Nye; How about showing me this manual switch at the next rally. How does it improve the cooling?

Fred

[Nye Thatcher]

Sorry about the error. I should have explaind that I installed the over-ride switch on the CONDENSER FAN not on the EVAPORATOR NYE

[Paul Dobbin]

My vacuum pump had a wire off, so when it called for the vacuum to close the doors under the dash, they didn't respond. THEN, the blower motor had a flat spot so if it stopped in the wrong place it would not restart! With all that fixed we did a 5000 mile summer trip and came home warm because it won't hold a full charge. Now I know why so many motorhomes run the generator and the roof air! But I'm still working on it!
Paul

[Paul Dobbin]

I had originally asked where the valves to fill the A/C were located.
(I was only able to find one under the front bonnet, so there was no
way to accuratley measure pressures)
Well, I had to have the compressor replaced because that's where
the freon leak was. The truck place that did it told me that with the
lone valve up front being so far from the compressor that the only place
to fill it properly was at the compressor.
Do you A/C guy's confirm that?

[gunworks]

Paul,

I don't agree with that statement. I recently went through the compressor replacement. The receiver/dryer is under the front bonnet with the charge connections. A/C shop had no problem evacuating the system, finding a leak in hose crimp, repaired same and recharged with 4 lbs 134A. All this was done at the front bonnet after the compressor was changed. My unit also had a bad pressure switch (screws onto the receiver/dryer) so that complicated the troubleshooting problem. As a side note I took coach to an Airstream dealer about a year ago and they had not a clue how to check or charge the system. I eventually did most of the repair and troubleshooting myself with the most valuable help of Acme Radiator in Northern Indiana. Parts were readily available and shipped prmptly. My wife can no longer sit in the front without a blanket. "It's too cold!"