RV Air Conditioning Troubleshooting Guide

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Your RV’s AC unit is one of its key components, especially if you are traveling in the summer. Unfortunately, accidents happen, and you may one day discover that your AC is refusing to work.

And the worst thing is that you can’t figure it out.

To help you with discovering the root of the problem, we are now going to give you a couple of tips on RV air conditioning troubleshooting. With them, you should be able to quickly discover what’s wrong with your AC!

How to determine if your AC unit has gone bad

First of all, you need to determine whether your whole AC unit has gone bad or not. If this is the case, then your only option would be to just replace it with a new AC. But if there are some specific components that have malfunctioned, then you’d just need to replace them to get your RV’s AC working.

To determine what is actually wrong with your AC, you need to troubleshoot it. Here’s the step-by-step process of how to do it.

Check the AC’s power

If your AC isn’t reacting at all when you try to switch it on, you will need to check if it gets power. First off, have a look at your 12V panel and check the condition of the fuse and whether the breaker has tripped or not.

If you run a thermostat with your AC unit, check it as well. Thermostats run on 12V, so if your thermostat doesn’t work, then it is likely that the 12V power is bad. And that’s a whole another issue that needs resolving.

One other thing that might have happened is that the fuse or the breaker shut off. This may happen if the power supply of the camping grounds is too weak to provide your AC unit with power.

Back in the day, many campgrounds had 15A power poles, which sometimes were too weak to provide sufficient power for AC units. Nowadays, campgrounds usually provide 50A service for modern AC systems, so lack of power shouldn’t be a problem.

If you find that your power delivery is all okay, it’s time to test the AC itself. But if there were any problems with your power source, you will need to resolve them first.

Check the capacitors

If the AC unit’s fan or compressor don’t start, it is possible that the starting capacitor is at fault. A bad capacitor has a number of symptoms:

  • The AC unit hums and tries to start.
  • The AC unit runs for a few minutes, and then the breaker trips.
  • The unit’s fan won’t start without a push.
  • The AC unit blows only hot air because its compressor is off.

The starting capacitor stores electricity in it to provide the fan motor and the compressor with the necessary power at startup. If the capacitor has gone bad, then it won’t be able to provide the AC’s components with that initial power boost.

The capacitor looks like a small battery, a button, or a flask. Some units come with just one capacitor, while others have several capacitors, one per each component.

You can test the capacitor with a multimeter. If the capacitor is alright, it will show a random value. If you keep the probes in place, this value will slowly decrease.

If the capacitor has gone bad, you should be able to replace it pretty easily. You just need to get a capacitor with the same voltage and model number and install it in place of the old one.

Before removing the old capacitor, memorize how its wires are installed. Don’t touch the terminals of the capacitor with bare hands.

In addition, before throwing the bad capacitor away, drain its charge. You can do this by connecting its terminals with a screwdriver that has an insulated handle.

Check the thermostat

If your thermostat is bad, then the AC unit won’t turn on. If your thermostat is wall-mounted, you can check its voltage with a multimeter.

If the AC unit turns on only when you touch the thermostat’s wires to each other, then the thermostat is definitely broken. But if the thermostat and your capacitors are alright, then it is the control board of the AC unit that may be bad.

Thermostats are easy to replace, so you shouldn’t have problems with them. As for the control board, you’ll most likely need professional help to get it working.

Check the fan/compressor

If everything has been alright with the AC unit’s power and the thermostat, the problem may lie in the unit’s fan or the compressor.

If the AC doesn’t blow air or blows it only at certain speeds, then the fan may be bad. If the AC blows air but it is warm, it is the compressor that may have gone bad.

A working compressor should turn on audibly and feel warm to the touch. If the compressor doesn’t work, then it is easier to just replace it with a new one.

As for the fan, it may be working funny due to several reasons. Maybe, by just cleaning or oiling its motor, you’ll get it working. If this doesn’t resolve the problem, then you will most likely need to just replace the fan motor.

Troubleshooting common AC problems

The RV AC unit’s motor is too loud

You may have noticed that your AC runs louder than it used to when it was new. Moreover, it may be too loud for your taste. Fortunately, the fix to this problem is pretty easy in most cases.

What to do

The primary reason for your RV’s AC unit being loud is that its rubber shock absorbers shifted from their place. If the shock absorbers interfere with the fan unit or the compressor coils, the AC will run loud.

To resolve this issue, you will need to remove the cover of the AC, find the rubber shock absorbers, and put them back in place. They shouldn’t rub against any running components in the AC.

Lubricating the AC’s motor may be another way of resolving the noise issue. If you can’t do this yourself, have a professional lubricate your AC’s motor.

There is ice around the RV AC

Ice around the AC definitely isn’t a thing that you’d want to have. First off, it will be melting and dripping down onto the floor, which will cause a mess at the very least. In the worst case, the dripping water will cause a short circuit.

In addition, even though the AC unit is producing ice, the air in the RV may be warmer than you’d expect.

What to do

The most likely reason for ice forming around the AC is low Freon levels. This may be caused by leaks, or maybe by Freon evaporating over time if your AC isn’t sealed well.

The first thing you’d want to do is check for any leaks. If you found a leak, you will need to find where it comes from. The trouble may come from anywhere in the cooling system, so you’d need to thoroughly examine it. Fittings and gaskets are common weak links in such enclosed systems, so they should be checked first.

If you find that the AC’s gasket is leaking, it doesn’t necessarily mean that the gasket is damaged. It may be that it isn’t bolted in place securely. So the first thing to do would be to tighten the bolts and then wait for a couple minutes to see if the problem persists.

If it does persist, then the gasket itself is most likely damaged. Replace it, and you should have the leaking issue resolved.

If there are no leaks, then you are pretty lucky. You’ll just need to top off Freon levels in your AC. This should resolve the ice issue and make your RV cooler.

The RV AC unit is leaking

Leaking is a pretty serious problem. Just like with ice, it is both a safety and efficiency concern. It is thereby important to resolve the leaking issue as soon as possible.

What to do

Now, if you notice a pool of water around the AC unit, it doesn’t necessarily mean that it is leaking. The evaporator coils in the AC unit evaporate the liquid coolant before it goes back into the compressor. When the coils get dirty or dusty, they may be unable to evaporate the liquid. This is what might cause dripping.

The solution to this problem is simple: you just need to clean the evaporator coils.

If this isn’t what actually causes the leaking, then you’d need to again check the AC’s gasket, just like it was in resolving the icing issue. If you remember, you need to tighten its bolts first and see if it solves the issue. If not, then the gasket needs replacing.

The RV AC unit gets hot

If you feel warmth coming from your RV’s AC unit, then something is clearly wrong. That isn’t how an AC should behave. In fact, your AC may get so hot that it just shuts itself down to prevent burning.

An AC that runs too warm won’t do its job, first of all. Secondly, it is a fire hazard, so you should resolve the overheating issue as soon as possible.

What to do

Most of the time, overheating is caused by lack of maintenance. If the internal components get covered by dust and dirt, the AC unit won’t be doing its job as it should. Thereby, clean the internals of your AC from all the dirt and dust, and you should have the overheating problem resolved.

The RV AC unit blows warm air

Your RV’s AC unit is there to deliver cool air, and it certainly wouldn’t be alright if it blew warm air. And since you’ll be using your AC in the heat of the summer, warm air definitely isn’t the thing that you want.

What to do

Your AC may deliver warm air because its motor is faulty. This basically means that its cooling system isn’t running. Here, you’ll have to determine whether the problem lies in the motor or your whole AC unit has gone bad.

Following the procedure we described in the beginning, check if your motor is getting voltage. If the motor isn’t getting voltage, then you should address a professional to repair it.

If the motor does get voltage though, it means that there is something else faulty in the AC. Most likely, it is the compressor. Again, follow the troubleshooting process we described above to find out what causes the problems.

The RV AC Smells

You certainly don’t want bad smells in your RV, right? But if you came across a strange odor one day, then it may be your AC unit that is at fault.

What to do

Before touching your AC unit, make sure that there isn’t something else in your RV that may be producing the odor. It may be your bathroom, or maybe you’ve left some food in your fridge for a long time. If you check everywhere and the odor persists, then it is most likely your AC unit.

Dirty filters in your AC could be responsible for all those bad smells settling in the RV. Filters need occasional changing, and if you’ve never done it or have replaced them a long time ago, your filters most likely need changing.

Aside from changing the filters, clear the radiator unit of your AC as well. It may also be a source of the odors.

The RV AC unit is constantly running

Modern AC units can be hooked up to a thermostat. When the temperature exceeds a certain threshold, the AC will kick in to bring it down.

If you one day discovered that your AC runs when it shouldn’t, then there may be a problem with it.

What to do

In the best case scenario, it is your thermostat that will be forcing the AC to stay on. If it delivers excessively high readings, the AC will be running constantly.

If the thermostat is all sound, it may be the AC’s circuit board that is responsible for this issue.

If your thermostat has gone bad, then you could just replace it. But if it is your circuit board, then you’ll have no other option than to address a professional to get it repaired or replaced.

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