RV AC Fan Not Working: Easy Fix For 9 Common Problems

AC helps you keep your cool. But if the AC fan in your RV does not work right you may lose your cool. The fan is one of the more important parts in your RV AC unit. Keeping it maintained will save you a lot of trouble and help you remain cool.

RV AC Fan Not Working: There are a lot of reasons why your RV AC fan does not work. The blades are out of balance, the motor doesn't perform well, or the blower doesn't put out the air flow you need. There also may be problems with the other AC parts that help make the fan run.

Those are just some of the reasons why your RV AC fan isn’t working. Some fixes are simple and take no time at all, while others require an experienced technician to help you. Just continue to read our article to find solutions to 9 other reasons why your AC fan does not work. Sometimes repairing a problem is not that difficult and you can save on replacement costs

RV Air Conditioner Fan Turns on and off Repeatedly

When you experience this problem it can get annoying. You also may be a little frustrated because you are not getting cool and you are wasting a lot of energy. There are four main reasons for your RV AC fan to turn on and off repeatedly:

  • The thermostats is on automatic or in the wrong place
  • The control board has gone bad
  • The evaporator coils have frozen
  • The air filter or condenser coils are filthy
  • The good news here is that these issues are not that hard to fix. For dirty filters and condenser coils, you simply need to clean them. A soft brush on your vacuum is needed for your coils and just wash or replace the filter.
  • For the control board, you would probably have to have it replaced and the evaporator coils would need to be unfrozen. As for the thermostat, you would need to find a better spot for it.

RV AC Fan Keeps Running - Won't turn off

This seems to be a common problem for a lot of RV owners. The main culprit may be the control board or your thermostat is faulty. On some air conditioners the speed settings do not allow the fan or compressor to shut off. To get those turned off, you have to switch your setting to automatic.

If your have already set your control to automatic then the problem is probably in the control board or thermostat. To fix both issues you would have to replace them once you found which one is causing the actual problem.

Another source of the problem could be your selector switch. These go bad far more often than the thermostat will. To check to see if this is a problem, you would need to use a multimeter.

Also check your AC input voltage to make sure it is running at proper levels.

Fan Runs but the Compressor does Not

When you run into this situation, there are several parts that could be the origin of your troubles. First, your compressor may have broken but this is usually a rare problem. Or it could be that the overload protector burned out,

Another factor may be the thermistor which checks the temperature of the outside air. Finally, there could be a defect in the relay board or the capacitor. The issue with the compressor and relay board is that they are often misdiagnosed and may not be the source of your problems.

You need to check the control board, the thermistor and the capacitor first. These are easy fixes to make and are the more common origins of trouble. A multimeter is needed to help you diagnose the issue. If it turns out to be any of the parts listed above, all you can do is replace when.

RV AC Fan Comes on With the Furnace

While it seems to be a major problem, in reality it is a very simple fix. If your fan comes on when the heat it turned on the problem is that the air conditioner fan is still in the on position.

To fix this all you have to do is turn your controls to auto and the fan should stop. If you have a single zone Dometic thermostat, here are the steps to handle this issue:

  • Press the on/off mode button until you get to the fan
  • Then press the +/- button to change the settings from high or low to auto
  • Next, press the on or off mode button until you select the furnace

RV Air Conditioner Fan Capacitor

The trick to fixing this issue is to understand that most air conditioners have 2 capacitors. One is for the run time and the other is designed only to handle the start function. The first one works with the blower fan and the second one works with the compressor.

Even though they have two distinct purposes, they can be tested in the same way. There are 2 tests you can do to check to see if they are still operating like they should.

Resistance testing- this is the quick way to find out if the capacitors are faulty.

Capacitance test- is the more accurate test and checks to see if the parts are meeting specifications.

To tell the difference between the two, the run capacitor is oval shaped, silver, and measures about 2 to 3 inches in length. The start capacitor is cylinder shape, black or silver in color and measures 3 to 4 inches in length.

Both capacitors can be found in the capacitor case in the top right hand corner of the air conditioner. That is if you are facing towards the front of the RV. A multimeter will be all you need to conduct both tests

The multimeter needs to be set to capacitance mode and the results should match the specs printed on the side of the capacitor. To do the resistance test, you need to switch the multimeter to Ohms mode. If the meter does not show progression to infinity, then the capacitor is leaking.

If the capacitors fail either test, then you will need to replace them.

RV AC Fan Won't Turn On

This can happen often and there can be a few reasons why this is taking place. The fan may not be able to spin and that could be due to bad bearings, Or the fan may not be getting enough voltage, and finally, the fan capacitor may be faulty.

Before you start trying to fix this problem make sure the power is off to your RV AV unit. Then go up and spin the fan blade. Usually the problem is in the capacitor and there is a risky test you can do to make sure it is the problem.

With the power off spin the fan. Then while it is still spinning, turn the power back on and see what happens. If it doesn’t continue then you may need to replace the capacitor.

The other problem is that the fan shaft rusts and gets stuck. All you would need is a pair of pliers and some penetrating oil to unstick the shaft. Then it should spin freely again

RV Air Conditioner Fan Vibration or Speed

There will be times where you are spending a quiet evening in your RV enjoying the cool air and all of a sudden you start to feel vibrations coming from your AC unit. You do not have to be afraid that your air conditioner is coming apart.

There just may be some simple issues that do not take a lot of skill or know how to fix. Vibrations can be caused by very simple problems. One is that the mounting bolts your air conditioner sits on have become loose.

When you check them just tighten them up a little. You do not want to over tighten them or you will be creating other problems for yourself. If the bolts are snug, then it might be the compressor hose that is causing the problem.These just need to be clamped to the housing.

Finally, any rubber parts designed to hold the compressor may have worn out and these would simply need to be replaced.

Now if you are having trouble with the current speed of your air flow, there are a couple of sources for this. The first thing is to see if you have an AC or DC driven motor. If it is AC then you have a serious fix on your hands.

You do not adjust the voltage level on an AC driven motor. What you need to do is alter the duty cycle. Then your problem should be resolved. If your AC motor is DC driven, then all you will need is a rheostat to settle the issue.

The only thing you would have to watch out for is if the humidity levels are high and you slow the air flow down too much, then your coils may freeze.

RV Air Conditioner Fan Replacement

Replacing the AC fan motor is not that difficult and if you have any mechanical skill, then it should only take you about 2 hours to so. Here are the steps to replace the motor.

Removing the old motor

Make sure the power to your Ac unit is turned off

Hook up an Ohm meter to check for the presence of AC current

Once you have seen there is no power coming to the fan motor, remove the screws holding the motor and squirrel cage

Remove the squirrel cage from the motor. This may be held on by Allen screws.

If there is rust on any of the crews, just use WD-40 or penetrating oil to loosen them up

Putting the new motor in:

Put the fan onto the new motor shaft, keeping the flat spot on the motor shaft in line with the Allen set screw on the squirrel cage

Tighten the Allen screws up securing the motor inside the squirrel cage

Put the motor and fan back into the AC unit

Replace and tighten the screws holding the fan motor in place. Make sure they are tight but not too tight

You may need to re-route the electrical wires at this time

Reconnect all wires and test the fan blade to make sure it is not rubbing against anything. They also should be centered

Put the housings back on and turn the power back on

Test the fan motor to make sure it is working correctly

How to Oil RV Air Conditioner Fan Motor

Depending on the type of RV AC unit you have, the bearings on your fan or AC motors may be sealed and self lubricating. But this does not mean that rust or corrosion does not get on some of the parts.

Rust and corrosion can stop a fan blade from spinning. Sometimes all you need to do to free the blade up is a few firm spins and the rust will let go. Or you can spray some silicone or other lubricant on the exposed metal parts and let that loosen the rust’s grip.

Exposed bearings are easier to oil and some penetrating oil, etc, would be the way to go

Some Final Comments

These are only 9 simple issues that may go wrong with your RV air conditioner fan. As you can see, most of the fixes are quite simple and do not need a lot of money to help solve the issues.

Most of the time, you should be able to handle the repairs yourself, even if you do not have a lot of mechanical skills. Replacement is the main answer for most of the troubles.

That is due to the nature of how RV air conditioners are constructed. In each case, you do not need a lot of tools but make sure you have the right meter on hand to check voltage and other electrical issues correctly.

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