RV AC Fan Not Working: Tips for a Proper Diagnosis

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When you are living in an RV on your own, you will need to be prepared for many unexpected hassles. One of them is an RV AC fan not working. It would not have been such a big of trouble had you been living in a regular home. But dealing with a non-working AC in a remote place sounds highly inconvenient.

There could be plenty of reasons for the RV AC fan to stop working. It could be the motor, blowers, a bad breaker, out-of-balance blades, or something else. To find out the troubling source, you need to perform a proper diagnosis.

RV AC Fan Not Working: Symptoms and Causes

The fan is an important part of any AC unit. Any problem with it means that the air conditioning won’t blow any air or perform at its best. Go through these symptoms and causes of an RV AC fan not working to understand the nature of the problem and take necessary repair actions.

The fan blows only on the low setting.

When this problem occurs, the AC fan does not work in any setting except for “low”. The air conditioning works and blows cold air but it stops as soon as you switch to the “high” setting.

RV AC fan issue
The fan sometimes blows only at “low” setting. (Credit: Freizeit-Ecke Weber)

Your first task is to check for blown fuses (you should do this for any kind of AC-related problems). Then, move on to the “run time” and “start time” capacitors in the fan motor. If changing them does not solve the issue, look into the high-speed winding of the fan. It’s burning out causes the fan to run only in the “low” setting.

However, the motor start is the most common cause for this fan-related problem. The capacitors there get degraded over time, making the motor fully or partially dysfunctional. Replacing the motor capacitors with new ones will solve this problem.

The AC fan does not blow; creates a loud humming.

Turning on the RV AC from the thermostat kicks off the system but the fan does not spin. Instead, a loud buzz comes from the unit. After engaging the breaker, it seems that the fan just locks up in its place.

This problem could be the result of a bad blower motor. A motor has several windings and if one of them goes bad, it cannot supply power to the next winding, causing the rotors to stop working. As a result, the blower fan does not get the power supply needed for rotating. The only solution is changing the motor but you can consult an experienced mechanic to see if they can fix the motor by repairing the malfunctioning winding.

If you are going to do the replacement by yourself, be careful when dislodging the motor. The capacitors in it store voltage for a long time even after cutting off the power.

The AC fan turns on and off again and again.

What’s more frustrating than the RV AC fan not working at all? The fan starts rotating only to stop working after a while, and the repetition of this cycle over and over.

This process consumes plenty of energy without actually making the RV interior cool. Such a problem could happen because of a malfunctioning control board or the thermostat set on “automatic”. A malfunctioning control board needs to be replaced.

Sometimes, setting the thermostat at the wrong place could also trigger this on/off frenzy. In that case, consult a technician to find a better spot for relocating the thermostat.

If the control board and thermostat turn out to be fine, move on to the evaporator coils. Frozen coils can interrupt the regular functions of the AC fan, causing it to stop and start frequently. Unfreezing the coils is the solution to this problem.

A dirty air filter or condenser coils can also cause the blower to turn on and off continuously. All you need to do to fix this issue is to clean the dirty components. Use a soft-bristle brush to remove the dirt and debris from the coils. The filter needs to be washed. If it’s too dirty to function, replacing will be the best option.

RV AC fan won't work
The fan could just turn on and off repeatedly. (Credit: I Bought a RV / YouTube)

The RV AC fan won’t turn on at all.

When the fan refuses to spin at all, you may need to spend a few hours to figure out the reason because there could be several reasons for this trouble. The culprit, in this case, could be the capacitor, bearings, or a low supply of voltage.

Bad bearings won’t let the fan rotate while low-voltage means it does not have enough power to function. On the other hand, there is a start capacitor for the AC fan. If it malfunctions, the fan won’t get the initial power boost to kick off.

Power the AC off for a few hours before starting the diagnosis because the capacitors can reserve electrical power for a long time. If you don’t know how to proceed, it’s better to call for expert help.

It won’t be difficult to do a checkup and pinpoint the source of trouble, given you have some experience in handling electrical components and tools. So, after a safe waiting period, access the AC’s fan and spin its blade. If it rotates without any problem, the bearings are not the issue here.

To see whether the capacitor is bad, turn the power on and see if the fan keeps rotating or not. You will need to change the capacitor if the fan stops with the power back on. On the other hand, a low-voltage issue needs to be fixed by changing the power switches, wiring, or breaker board. This is the job of an expert electrician.

Another possible reason for this problem could be the rust and dust in the fan shaft blocking the blades. Fixing this is easy as you will need penetrating oil and a pair of pliers. Use the oil to soften the sticky gunk and then apply force with the pliers to make it spin freely again.


Many AC units are replaced untimely because of the RV AC fan not working. But you can easily fix this issue by following the diagnostic tips mentioned above and save plenty of money.

About Chris Coleman

Chris Coleman is an interesting travel blogger and outdoor photographer with a great sense of humor. He owns an RV Accessories shop in New York City so he has the knowledge necessary to provide thorough reviews and give advice on how to choose the right products for RV travel. He puts all that RV knowledge and experience to good use in his sharing posts. Besides product buying guides/reviews, Chris also writes informative articles, how-to articles and RV camping guides in his own interesting viewpoint. Chris’s blog is one of the most reliable information sources for RV campers no matter if you're an expert or a determined beginner.

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