A/C question

[lazerdms]

I have a 2013 crossroads zinger issue is the a/c is not cooling its blowing and the compressor is coming on. could this be low Freon or do I need to look somewhere else

thanks for any help

[j-d]

If you have Hot and Cold lines from and to the Compressor, something is wrong with air flow. Could be Ducting, could be a really dirty Evaporator or Condenser, or very clogged Filters.

Condenser is easily cleaned with the Shroud off. Evaporator requires taking some of the forward housing off. With a Make/Model, we could tell you more about how to get in there. Our Coleman Mach has a panel that starts at the front, slopes up, and flattens out over the Fan Housing. The sides of the housing don't have to come off, just that upper piece. Yours may be different. Keep track of the several types of sheet metal screws that Coleman uses.

[wa8yxm]

lazerdms wrote:
I have a 2013 crossroads zinger issue is the a/c is not cooling its blowing and the compressor is coming on. could this be low Freon or do I need to look somewhere else

thanks for any help

Sadly this is one of those questions to which the answer is YES.

I know that does not help. But it MAY be low on freon (Well it's not Freon any more, but Refrigerant.. They still call it Freon though).. Or it may be something else.. here is the suspect list.. As it happens I'm on a tribble hunt just now with a different A/C unit

Refrigerant (my Tribble as it turned out)
Compressor
Expansion valve
Condenser (This is the outside or HOT coils)

IF the compressor is running.. Then on a RV system (mine is a car) the odds are the Condenser has not been cleaned since it was installed.

Go topside, take a SMALL soft bristle brush, an Air hose and/or water hose (I prefer air but sometimes you need water) with jet nozzle and a phillips head screwdriver (#2) with you

Or better yet, Take the screwdriver and brush and a lenght of string and pull up the hoses later. (partner ties string to hose)


Remove the outer cover (Cowel) and set aside.. Remove the inner cover on condenser and inspect.. Clean if needed, clean everything else as needed

If you blow water or air into condenser be very careful to blow STRAIGHT in, combing out the fins is a witch of a job.

Note also: The above is the "No Cost" suggestion.. If that's not the issue, the other possible problems all cost $$$$$$$

A new A/C runs in the neighborhood of a Kilo-Buck installed.

[lazerdms]

I checked the lines last night and one was cold and the other was hot will check more today

[j-d]

dougrainer wrote:
RV AC units can be checked very easily with a Amp meter. Compressor Amp draw based on Ambient temp will tell you the state of the system. Doug

lazerdms - Since you're a New Member...

First, Welcome, shoulda said that sooner, and

Second, By way of introduction, Doug, in addition to Senior Member, is an experienced RV Tech, over 30 years experience. Listen carefully to his advice.

Clamp On AC Ammeter (known to many as Amprobe) is cheaper than a service call and less invasive than a test port. As I mentioned earlier, HF's cheap ones will measure AC Amps and also serve as a very basic Digital Multi Meter (DMM, sometimes called Digital Volt Ohm Meter or DVOM). If you want to be able to do more RV troubleshooting, more expensive "amprobe" type units will measure DC Amps, Capacitance (good for A/C troubleshooting) and Frequency (good for Generator troubleshooting).

Big Boxes like Lowes and HD will have clamp-on's. Sperry Snap is a common brand.

[dougrainer]

Kayteg1 wrote:
When compressor is running and is not cooling it is low Freon or bad compressor.
Ufortunately there is no easy way to test as AC are build without valves.
You need to add a valve for testing. Those go for about $10 on ebay.

WRONG. RV AC units can be checked very easily with a Amp meter. Compressor Amp draw based on Ambient temp will tell you the state of the system. Doug

[lazerdms]

I will check all this out tomorrow and give update thanks for the help

[Kayteg1]

Low current draw can indicate low Freon, or bad compressor spinning freely.
You are back to square 1.

[j-d]

Kayteg1 wrote:
When compressor is running and is not cooling it is low Freon or bad compressor.
Ufortunately there is no easy way to test as AC are build without valves.
You need to add a valve for testing. Those go for about $10 on ebay.

True, but... We can take a clamp-on AC (alternating current) ammeter and check the current draw of the compressor. Compressor should be labeled (or we can use Model Number and look up) the Running Amps and the Locked Rotor Amps for the compressor. Requires having the Ammeter. Cheapest is Harbor Fright, not much over $10 on sale, maybe $20 regular price. The Locked Rotor Amps is if the compressor is stuck, cannot run, and is likely to be around 60-80 Amps on 120 volts AC. What we're interested in is Running Amps. Should be low teens (12-15) and if SO, then the compressor is probably normal and the system is probably charged. If Running Amps are HIGH, compressor isn't normal, maybe coils are dirty, maybe fan not running, fan blade shot, etc. If Running Amps are LOW, might be low or discharged on refrigerant. Compressor could be shot with failed valves. There are also rare cases where the motor part of the compressor disconnects from the actual compressor part. Again, compressor has to be replaced.

Yes, you can install test ports. Then you need A/C gauges to test, and those ports usually cause leaks. Do what you want, but I'd really like to hear what you learn on minimally invasive inspection and testing.

[j-d]

Can you get topside and remove the plastic shroud from the A/C? SAFELY?

Compressor will have two pieces of tubing between itself and the rest of the A/C. The larger one should be cool with compressor running, and the smaller one should be hot. Are they?

You didn't say it's a Heat Pump so I'll trust it isn't so there's no reverse valve to cause trouble.

What's the Make, Model, Size of this A/C?

Have you ever cleaned its coils? The condenser coil at the rear of the unit is easy to get at. Clean obvious stuff from fins with soft brush. Then spray with 409 or the like, rinse with medium pressure water. The evaporator coil (that provides cooling) is inside the front of the A/C inside some shrouding. Same process but you need towels to keep water from going down into the coach. You'll see the condensate drain tray under that coil. Clean that too, and make sure your rinse water drains out of that tray onto the roof.

There should be a Freeze Sensor near the evaporator coil. Those can get out of position and shut the compressor off prematurely, but you say your compressor is running.

Please try this and report back.

RV A/C units are a fully sealed system, like a home refrigerator or window A/C. They CAN leak refrigerant but it's rarely the problem.

[Kayteg1]

When compressor is running and is not cooling it is low Freon or bad compressor.
Ufortunately there is no easy way to test as AC are build without valves.
You need to add a valve for testing. Those go for about $10 on ebay.