Troubleshooting a Camper Air Conditioner: Methods to Try Today


When your camper air conditioner is on the fritz, you’ll want to know how to fix it fast. It’s either that or sweat through another day and night. How do you get your camper AC up and running again?

Top RV air conditioner troubleshooting tips:

  • Replace freon levels
  • Test circuit board or thermostat
  • Clean evaporator and condenser coils
  • Replace filter
  • Check capacitors
  • Run motor voltage test
  • Reset high-pressure safety switch circuit

As you can see, we have an assortment of the most common reason your RV ac unit is blowing out warm air. Keep reading for more information!

10 Ways to Troubleshoot an RV’s Air Conditioner

Low Refrigerant Levels

The other day, you noticed a very odd phenomenon with your camper air conditioner. The unit was partially encased in ice. 

You naturally panicked when you saw this, and rightfully so. 

After all, despite the prevalence of ice, your air conditioner is not running any colder than usual. If anything, it might be producing warmer air than it should.

Air conditioners use freon, which is a commercial term for refrigerant. The refrigerant is what helps the AC produce cold air, as it evaporates repeatedly until it’s cooled.

Should refrigerant begin leaking from your camper air conditioner, that can explain why the unit has begun to freeze over.

You’ll have to take your AC to a technician if it’s leaking, as it’s likely an internal component that’s caused the leak that you can’t easily reach.

Before you do that, though, check the refrigerant levels. If they’re low, then your AC can blow a lot warmer. Low levels can also contribute to the abovementioned ice issue.

Once you top off the refrigerant in your camper air conditioner, both issues should disappear. 

Test the Circuit Board and/or Thermostat

Perhaps your air conditioner has no problem producing cold air. The issue is that it doesn’t stop. 

You’re not sure why that is, as your camper feels cold enough, yet your AC still continues to chug along. 

You’re worried that the nonstop running will cause the unit to burn itself out sooner than later.

You are indeed correct, as that could happen. Thus, you want to troubleshoot an issue like this as soon as you can.

First, we’d recommend inspecting the camper air conditioner’s circuit board. 

The circuit board is like the brain of your air conditioner. It’s a board with wiring for the resistor, capacitor, transistor, and other components. It’s usually green, but not exclusively.

If the circuit board has gone bust, then the air conditioner might no longer be able to regulate its fan speed or temperature. 

Without control of the latter especially, the air conditioner will keep running and running.

You can’t fix a damaged or malfunctioning circuit board, but being able to diagnose the issue will help the technician who repairs your AC.

If the air conditioner is still running for longer than it should, it also doesn’t hurt to check the thermostat. 

It could just be that the thermostat is set to a lower temperature than the AC can maintain (especially if it’s very hot out). It’s still trying though, hence why the air conditioner won’t turn itself off.

Even if you do assume something is wrong with the thermostat, this is yet another issue that you yourself can’t fix. 

Clean the Evaporator and Condenser Coils

Your air conditioner is comprised of two major components, the condenser and the evaporator. 

The condenser, which is sometimes referred to as the compressor, will gather heat so the air that comes out of your AC isn’t hot.

The evaporator takes the heat in your camper and absorbs it, which also makes your vehicle feel cooler.

Both these components have coils that are usually accessible even if you’re not a technician. The coils can get gunked up by debris such as leaves or dirt. 

When debris blocks the coils, that impacts how well your camper air conditioner works. You may notice issues like warmer air coming out of the AC. The air conditioner can even stop working altogether.

At least several times per year, even when nothing is wrong with your air conditioner, you want to begin prioritizing keeping those coils clean. 

To remove debris use a soft bristle brush or a vacuum cleaner with a brush attachment to gently remove any loose dirt, dust, or debris from the coils. Be careful not to bend or damage the delicate fins on the coils.

Deep cleaning: If the coils are heavily soiled or clogged, you can use a coil cleaning solution specifically designed for RV condenser coils. Follow the instructions on the cleaner carefully. Typically, you would spray the solution on the coils and allow it to penetrate and loosen the dirt and grime. Then, rinse it off thoroughly with water.

Airflow problems, such as frozen evaporator coils, soiled coils, clogged air filters, and incorrect fan speed settings, can contribute to the release of warm air from the ceiling vents.

Replace the Filter

Whether it’s your air conditioner at home or the one in your camper, it has a filter. The filter’s job is to catch contaminants in the air, everything from pollen to grease, dust, and smoke. 

By entrapping the contaminants, the air that comes out of your AC and into your camper is a lot cleaner.

You’re mostly hurting yourself and your fellow passengers when you fail to keep the filters clean. You’re breathing in that very dirty air.

However, your AC can suffer too, as the dirt and debris that a filthy filter cannot catch can prevent the air conditioner from blowing cold air.

At least every two weeks and no more infrequently than once a month, you should check the filters. 

Some filters are reusable. In that case, you can wash them with soap and water, dry them, and then replace them. That said, be sure to use a gentle hand. Once you rip a filter, it’s game over.

You’ll have no choice but to buy another one.

For single-use filters, just change them out monthly or twice monthly to keep your camper air conditioner running its best. 

Check Both Capacitors

Your air conditioner maybe wasn’t sounding so great the last time you used it, but it certainly didn’t seem to be ailing enough to indicate that it would stop working. Yet that’s exactly what’s happened. Your AC just won’t turn on.

One such issue that could have caused a failed camper air conditioner is trouble with the capacitors. 

The capacitors trigger the electric energy that your air conditioner needs to turn on. The capacitors included with your AC are a start capacitor and a run capacitor. 

If you notice that your air conditioner tries to turn on but only hums, then you can narrow down your issues to something being wrong with one or both of the capacitors. They’ve likely gone bad.

To confirm, you can use a multimeter to test the capacitors. When the capacitors fail to generate or hold a charge, you have to swiftly replace the broken one. 

We’d recommend buying a manufacturer capacitor to ensure it works with your air conditioner.      

Run a Motor Voltage Test

Another camper air conditioner troubleshooting tip we have for you is to test the voltage from the motor. 

If the motor isn’t getting enough volts or isn’t receiving any voltage at all, neither is very good. 

More than likely, your air conditioner isn’t blowing out the requisite cold air to keep your camper nice and chilly.

Like a few of the other areas we’ve discussed throughout this guide, if something is wrong with the voltage of your AC and/or the motor, you cannot repair it yourself. You need to contact an air conditioning technician.

Reset the High-Pressure Safety Switch Circuit

Some air conditioner models have a high-pressure safety switch circuit. 

This safety monitor tracks the high-pressure levels of the air conditioning loop. Then, depending on the reading of dual pressure thresholds, the switch can turn the compressor on or off automatically.

It takes a lot less than you’d think for the high-pressure safety switch circuit to disable the compressor. For instance, if your air filter hasn’t been cleaned or replaced in months, that’ll do it. 

You’ll have to manually reset the switch, and how to do that varies depending on the air conditioning model. 

Sometimes, all you have to do is reset the power supply to your camper. 

The instructions might be more in-depth than that though, so be sure to refer to your owner’s manual for how to get the high-pressure safety switch circuit to re-enable power to the compressor.

By the way, if you don’t fix the conditions that caused the switch to disable the compressor in the first place, then it will only be a matter of time before it happens again.

You should clean your air conditioner’s filters, as we talked about before, but be aware that other causes can trip the high-pressure safety switch circuit as well. 

Lubricate the Fan Motor

Although not all camper air conditioners do, some models might need blower or fan motor lubrication. 

Before you assume that yours does (and potentially gunk up the AC even more), check your owner’s manual or contact the air conditioner manufacturer. You should also be able to ascertain the appropriate type of oil to use as well. 

If you need SAE 20 non-detergent oil, that’s the case for most camper air conditioners. You should be able to buy that oil at automotive stores, or, at the very least, online through your favorite retailers. 

Replace the Shock Absorbers

In some cases, your air conditioner might work fine. It’s just that it rattles, hums, and makes a lot of noise.

You don’t mind this so much during the daytime. Sure, sometimes you’re interrupted from enjoying the sounds of the birds chirping right outside your window by your loud AC, but it’s not so bad.

It’s at night that you have the most trouble. Even with earplugs, sleeping with your very loud air conditioner is hard. You toss and turn most of the night and don’t feel rested by the morning.

Fortunately, an easy problem such as an overly loud camper air conditioner has a very simple fix. 

Check the rubber shock absorbers that came with your AC. 

Through time and use, the shock absorbers can move out of place. When they’re too close to the compressor coils or the fan, then your air conditioner will rumble or grumble whenever you run it. 

All you have to do is take off the front cover of the air conditioner and reposition the rubber shock absorbers. Then put the cover back and try running your AC again. 

It should be a heck of a lot quieter, that’s for sure!

Just to note, although this isn’t a very high-priority issue with a camper air conditioner, a loud AC is still not a problem you want to ignore. The unit will only become louder with time, prohibiting you from resting well. 

Tighten Gaskets 

We talked earlier about a frozen camper air conditioner and how freon leaks could cause that issue. 

Well, your AC is indeed leaking, but you don’t think it’s refrigerant that’s seeping out of the unit. It seems to be water.

Atop the air conditioner is a gasket. The bolts of the gasket can loosen after a cooling season or two. By tightening them, that might be enough to stop the leakage.

If not, then you’ll have to replace the gasket altogether. That’s something you can do on your own, and it shouldn’t be too terribly expensive either. 

3 Signs That It’s Time to Replace Your Camper Air Conditioner

Just because your camper air conditioner is functional doesn’t mean you shouldn’t think about replacing it. 

If the following issues occur regularly and the above troubleshooting methods did not help, then you need to begin budgeting for a new AC.

You Get It Fixed Several Times Per Year

A camper air conditioner, as an HVAC unit, will need repairs, of course. These should occur periodically though, not several times per season every season. 

If your AC is in for repairs more than twice per year, then it’s time to think about upgrading. The money you’re spending on repairs likely could have already bought you a new camper air conditioner or several.

Don’t sink another penny into your dying AC!

The Airflow Isn’t Good

The older your air conditioner gets, the less airflow that usually comes out. If the AC cannot push out air at a rate sufficient to cool your camper, then that can leave you and your fellow guests sweating. 

You could spend a pretty penny to get the air conditioner serviced, but this is one of those issues that’s so expensive that it doesn’t warrant a repair. Instead, it warrants a replacement. 

It’s Old

The average lifespan of a camper air conditioner is between 10 and 15 years. If yours has lasted twice that or close to it, then you can’t ask any more from the unit. It’s time to bid it adieu and buy a more efficient air conditioner. 

Final Thoughts 

RV ac system can have all sorts of issues, from not blowing cold air to operating too noisily or even running nonstop. We hope the troubleshooting tips we provided for you in this guide help you pinpoint what’s wrong with your AC and get it working again!

Geoff Southworth

I am a California native and I enjoy all the outdoors has to offer. My latest adventures have been taking the family camping, hiking and surfing.

Recent Posts

outdoortroop-21 outdoortroop-20