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Doc007 · 12-03-2022, 09:48 PM

2011 AB. Sometimes it works and sometimes it don't. Sometimes it runs a while and then stops but other times it doesn't run on start up. The little push buttons light up so it is getting power. Where should I start looking? Would you take it to an A/C repair shop or an RV repair shop if you can't find the cause.

8.3Oilbuner · 12-03-2022, 10:51 PM

Hi Doc007; Good evening. Well, there could be a couple of reasons for the dash A/C not working as you described. The best way to know is to put a set of A/C pressure gauges on the system to know where you are at, or how much freon is in the system. When you say it works and then it doesn't, to me, it sounds like the system could be low on freon. The static pressure in the system changes with the air temp. outside. The higher the outside temp. the higher the pressure in the system and vise/versa. There is a low-pressure switch in the system to protect it if the freon charge gets too low. You could be just on the boarder line of when it is warmer outside the pressure in the system is enough to close the low-pressure switch and allow the compressor to run, although you should notice not a lot of cooling. If the outside temp. is lower, it could be just enough to open the switch and not let the compressor run.

This is just one reason you for the symptoms you are having the problem with the dash A/C and there could be more. To me the place to start is with the A/C pressure gauges. If you are not familiar with how an A/C system works I would take it to an A/C shop and get the job done right. I have been working around dash A/C systems since 1970 so I get by.

You know, just enough to be dangerous! Hope this get you going to a fix and good luck. Also, Happy Holidays!

code2e · 12-03-2022, 10:57 PM

Quote:

Originally Posted by Doc007

2011 AB. Sometimes it works and sometimes it don't. Sometimes it runs a while and then stops but other times it doesn't run on start up. The little push buttons light up so it is getting power. Where should I start looking? Would you take it to an A/C repair shop or an RV repair shop if you can't find the cause.

By far the most common issue is system low on refrigerant. You don't necessarily have a leak that needs repair. Being 12 years old, the system has lost some of its charge since A/C hoses are porous.

The only accurate way to fill a system is to evacuate it empty and fill with its specified amount of refrigerant. I do not recommend just adding a "can" of Freon yourself. There is no way for you to know if system is full, low or overfilled.

I would go with an A/C shop rather than an RV shop. The A/C shop will have the most experience and best equipment.

I have retired from 50 years as a professional mechanic. Recharged many 1000's of systems

Jon_C · 12-03-2022, 11:11 PM

If it either works and cools fine or doesn’t work at all, it sounds like a intermittent elecrical connection on the compressor circuit.

Causes could be low pressure cutout switch or thermostat keeping compressor from engaging. these will be near and on the evaporator housing. Compressor circuit runs thru each of these so any intermittent issue with one or a connection cuts off compressor.

If you can see the front of compressor, if the whole thing is rotating then it’s engaged and working and should be cooling, if the center section is not rotating and you have the air on then the circuit above is not allowing 12v thru to the compressor clutch and needs to be troubleshot. Or the clutch on compressor could be bad.

Also make sure your condenser fan is working that will cause very little cooling, on mine the fan is on the same circuit as the compressor so if its running the compressor should be also.

If compressor and condenser fan is running and no cooling then its not an electrical issue as long as the fan in dash is working and air coming out of vents, then need to connect gauges and check refrigerant pressures

shootist · 12-03-2022, 11:33 PM

Your incoming vent air could be staying on heat or the heater valve leaking hot water through. Feel the heater hoses when warmed up fully. If the valve is closed one should be a little warm and the other air temperature. The way I check the problem is by clamping one hose off and stop the water flow. The check is free , so if nothing changes move on to checking for low freon. If the shop says your pressures are good then maybe a blockage in the system. Side radiator shouldn't have a separate condenser fan. The only other possibility is electrical failure, pump clutch, high pressure switch, low pressure switch, controls, thermostat. I've never seen electrical cause an intermittent AC problem but I am sure it can.