2008 sea breeze on a workhorse chassis AC problem

[davenav1953]

The dash ac quit working on my 2008 National sea breeze.
It appears there is Freon in th system because when you remove the filler caps on the high and low side hoses and push in on the Schroeder valve, Freon comes out. The Freon that comes out of the high side hose is under much more pressure than the low side.
When you turn the ac on with the engine running, the ac clutch on the compressor doesn’t turn on.
I would like to either test or replace the ac relay in the dash, but the manual doesn’t say which relay is for the ac. There are three relays in a row next to the fuse panel in the dash.
Does anyone have any suggestions?

[MrMark52]

If the compressor hasn’t run then pressures will be balanced throughout the system, and cannot be higher on the high side and lower on the low side.

Temporarily jumper the low suction pressure switch on the suction line just after the King valve. If the compressor engages for a few moments then cuts out, the system is low on refrigerant.

The A/C relay is the middle of the 3 relays, left hand side of the “under hood fuse panel”. The action of that relay is controlled by the ECM.

[Ron03Allegro]

It is the correct amount to make cold.

My 2003 chassis AC was blowing but not making cold. Prior owner just let it go unserviced.

I got a can of freon with gage on it, the directions do not teach on well.

The trick hook up the can, run the ac after idling for a few minutes, let ac just run for 3 minutes.

Do you hear the ac compressor cycling a lot? I believe that means I don't detect enough freon. the gage bounces.

Add some coolant see the gage come closer to filled green? The cycling is not as much. Slowly add to find the enough but careful not to much.

Mine works great! I got lucky, hope you do too!

[davenav1953]

Do you know how much Freon that system holds. My guy that is going to check the system out was asking if I could find out

[MrMark52]

An ‘08 probably has a sticker on it somewhere indicating refrigerant type and amount.

A good serviceman knows that, and there is no way to know how much refrigerant is in the system in order to “top it off”.

A good serviceman will know how to add charge to the system to achieve performance.

[davenav1953]

Ok thanks
I’ll look around the evaporator in the engine compartment to see if they put a sticker in there.

[davenav1953]

I did the jumper wire on the wires going to the low side switch and it didn’t make the compressor clutch kick in so I figured there must be enough Freon in the system.
The next idea I had was to run a jumper wire to the hot wire on the ac clutch.
The system is putting out cold air and the hoses have the right temperature when you touch them with your hand as the system is running.
Coming from the compressor to the condenser the line is hot to the touch, the line coming from the evaporator is cold to the touch.
The problem must be what ever turns the compressor clutch on.
I replaced the middle relay and it made no difference.

[MrMark52]

Take a look at the climate control panel inside of the coach.

The fan switch design is sub-par for powering the fan/blower and depending on the switch they used in your coach, power for the compressor goes thru that switch.
If the back or terminal side of that switch is discolored or blackened, that might be your problem (I do have a solution for correcting that design).

Post a picture of your climate control panel.

Also confirm the manufacturer of the coil box (I suspect it’s Evans or Evans-Temcon).

There may also be an evaporator cold control switch mounted to the outside of the coil box which has a capillary sensing tube pushed up inside of the evaporator in the coil box.

[davenav1953]

Ok it will be a couple of days before I can get out to my storage unit to check on it.
The control unit you are talking about is the the knobs in the dash that turns the ac on and adjusts the temperature, right ?

[MrMark52]

Correct. You really need to access the back of the panel to look at the back of the switch.

PM me your email address and I can send an example picture of what a bad switch looks like.