Community Forums

NVMike · 08-21-2015, 02:27 PM

Had the AC looked at about a year ago. They put in 1lb of R134. Worked pretty good for a while. Then it just started blowing ambient air. Heater would work ok. Then one trip we started out early and I used just the vent with fan. Very comfortable temp. Got to our destination and it was hot! The AC had been working in the vent mode! Now, nothing but hot air in AC, vent and of course heat modes. Anyone have any ideas before I go to a pro? Thanks.

dwmcg · 08-21-2015, 02:37 PM

Possible a fuse is blown but usually if a fuse blows there is a reason for it. Mine blew because the compressor clutch burnt up. New compressor, dryer and Freon fixed that problem.

greystroke · 08-21-2015, 04:11 PM

Check your condenser fan underneath the chassis. If it stops no cooling. Easy to check

Bob/Becky D - VA · 08-21-2015, 05:27 PM

Had the same problem in my Itasca. Turned out to be a vacuum leak in one of the lines going to the control unit.

NVMike · 08-21-2015, 07:03 PM

Quote:

Originally Posted by greystroke

Check your condenser fan underneath the chassis. If it stops no cooling. Easy to check

But, why does it blow hot air in the vent position? Granted if there is a condenser problem why doesn't it just blow ambient when in AC position?
Of course I will check the fan first chance. Thanks for the tip.

NVMike · 08-21-2015, 07:05 PM

Quote:

Originally Posted by Bob/Becky D - VA

Had the same problem in my Itasca. Turned out to be a vacuum leak in one of the lines going to the control unit.

Makes sense. Does the vacuum line operate the baffles?

Papa_Jim · 08-21-2015, 07:29 PM

Possibly the water control valve for the heater is not sealing when closed, and is allowing hot coolant to flow through the heater core, even tho the temperature selector is set on cold.

Worth checking.

Jim

Bob/Becky D - VA · 08-21-2015, 07:49 PM

Quote:

Originally Posted by NVMike

Makes sense. Does the vacuum line operate the baffles?

On mine they do. Control the baffles between heat and cold. Others may have electronic control though.

jacwjames · 08-21-2015, 08:06 PM

In most cases went the vacuum system fails that controls the vents the system will default to the Defrost mode. Do you have cold air coming out of the defrost ducts?? Usually with a vacuum leak you will hear the vacuum generator clicking.

With the RV running and the AC on and set to cold check to see if the AC compressor is running (if you can see it). If it is not running you may be low on Freon again. You could try to put in some, you can buy a charge kit from Walmart pretty cheap that will have the gauge on it. Try adding as per the directions. This would be the cheapest thing you could try.

If it solves your problem for the short term it would indicate some sort of leak. The next time you have to had Freon I would get a can of the ultraviolet dye so you can find the leak to get it fixed.

I was chasing a leak on my Suburban and finally put the dye in it and found the leak the next day.

greystroke · 08-21-2015, 08:42 PM

Quote:

Originally Posted by NVMike

But, why does it blow hot air in the vent position? Granted if there is a condenser problem why doesn't it just blow ambient when in AC position?
Of course I will check the fan first chance. Thanks for the tip.

Kind of thinking it might be a vacuum problem.

NVMike · 08-22-2015, 10:56 AM

Quote:

Originally Posted by Papa_Jim

Possibly the water control valve for the heater is not sealing when closed, and is allowing hot coolant to flow through the heater core, even tho the temperature selector is set on cold.

Worth checking.

Jim

Where is the control valve located, and what does it look like?

Papa_Jim · 08-23-2015, 01:33 PM

Should be on passenger side behind generator door. Have someone work the heater hot-cold control while you look for the water valve. The cable attached to it will be sliding in and out.

The cable may only need adjusting so that the water valve will entirely close when heater control is set to 'cold'. Or, the water valve may be leaking internally so that it is allowing hot water to leak through when it is closed.

Jim

NVMike · 08-23-2015, 07:23 PM

Quote:

Originally Posted by Papa_Jim

Should be on passenger side behind generator door. Have someone work the heater hot-cold control while you look for the water valve. The cable attached to it will be sliding in and out.

The cable may only need adjusting so that the water valve will entirely close when heater control is set to 'cold'. Or, the water valve may be leaking internally so that it is allowing hot water to leak through when it is closed.

Jim

I just got settled in for a few weeks stay near my kids. Next time I fire up the beast I will check all of the suggestions. Till then.....

YC1 · 09-01-2015, 02:29 PM

My compressor is on the same line as the AC condenser fan. If the fan is not running due to a blow fuse the compressor will not kick in either. Mine is a later model so your mileage may vary. Definitely worth checking to see if the fan is running. If it is not, check fuses.