How To Fix A Stuck Relay On AC Unit In A Step By Step Way Like A PRO?

A relay on your AC unit is something that gives power to it. If something is going wrong with your relay then your ac compressor won’t receive any power. This means your AC unit won’t be able to function at all.

That’s why learning how to fix a stuck relay on an AC unit is crucial. It will save you from a lot of harassment, time, and money.

Now, there are usually two issues with relays. They either get damaged or they can get stuck. and when stuck, your AC won’t turn off or turn on. Here I will mainly walk you through fixing your home AC relay switch. So, let’s get going.

Fixing A Stuck Air Conditioner Relay Switch

how to fix a stuck relay on AC unit

Well, this might come in as a wonder but one solution to fixing a stuck relay is just to knock it a couple of times. Although this is something that works only sometimes if the issue isn’t major.

Also, you might notice something stuck on the relays. By cleaning the dirt or debris from the relay you can unstick them very easily.

To do that all you need is the AC fan relay switch location. You can find that on the user guide of your AC unit. Or you can look it up on the internet.

They are typically on the sides or the back of an AC unit. Now, if you have tried these solutions and they don’t work then you have to move on to the next thing. You have to replace the stuck relay.

It’s best if you opt for a professional technician to get the job done. However, I will walk you through the steps of replacing a relay.

This is also the solution if your relay is damaged. Here’s how you replace the home AC relay switch-

  1. Get The Right Relay

Check the new relay you have bought and see if it matches the old one. The shape, design, and electrical specification of both the relays have to be the same.

So, consider this factor before you replace the relay.

  1. Disconnect Power

First and foremost, you have to turn off the circuit breaker of your air conditioner. Or you can disconnect the switch if you want.

The reason is relays are the intermediaries to transfer electricity throughout the air conditioner. So, it can harm you a lot if you don’t turn off the power.

  1. Keep Track of Terminal ID

On the relay, you will see some wires. You have to tape all of them. Try using masking tape for this purpose. Because you have to write the terminal ID on each of the terminals.

Then matching to that you have to draw the relay and the terminals according to your wiring. This will help you keep track of the relay and its wiring that you did.

  1. Pull Terminal Connector

Now, get a needle nose plier and pull the terminal connector of the wires. Make sure that you are gripping the connector. Gripping the wire can damage them completely.

  1. Unscrew The Relay

The relay will probably be screwed into the AC unit. All you have to do is unscrew the relay.

  1. Install The New Relay

Remove the old relay from the unit and place your new relay in its place. Then, use the screwdriver to screw the relay back into the air conditioner.

  1. Final Touch

Here’s where the masking tape comes into use. You will need to push the wire into the terminals based on the ID numbers that you wrote on them.

Or you can use the drawing you did. To push the wires, you will need to use the pliers. Keep in mind that you have to completely insert the wires into the relay terminals.

Replacing the stuck relay is the best fix for this problem. And it doesn’t cost too much either. You might have to spend somewhere around $20 to $100 for a new relay.

While buying a new relay you have to ensure it matches the existing relay on your ac unit. The voltage, amperage, shape, size, design, and sometimes even the time delays have to match.

So, make sure to buy one that exactly matches all the factors of your relay. Now, watch this video to make yourself more confident.

The Signs Of A Bad Relay

How would you know a bad relay is causing your AC to malfunction? There are so many reasons that your AC may not work.

Boiling down to one reason can be tricky. However, you can tell if the relay is bad or not through some signs. Here they are-

  • If the relay is not working properly you will get inconsistent cooling. The work of the relay is to transmit the command you give to the thermostat. When you see your commands aren’t getting through you should immediately check up on the relay.
  • Sometimes the AC won’t turn off due to a stuck relay. A stuck relay can stay in the open state and cause some of the components to not turn off. This results in your AC not turning off at all.
  • Another sign is the opposite of the previous one. Your AC won’t turn on if there is something significantly wrong with the compressor relay. As the compressor won’t work if it doesn’t get the power it needs. So, you can say that there are issues with the relay in this case.

Knowing these signs can help you determine the problem. And as you saw with some expertise you can fix the issue by yourself.

However, without any knowledge, you always have to rely on professionals.

Stuck AC Relay Switch: A Note

The basic function of a relay is to open up different electric circuits so that all the components can work properly.

One of the crucial components that the relay provides power to is the fan. Naturally, the relay is supposed to open and close to provide power to the component.

But sometimes it gets stuck in one position. This disrupts the communication between the thermostat and the fan.

As a result, no matter what command you give through the thermostat your ac won’t receive any of them.

Frequently Asked Questions (FAQs)

What does a compressor start relay do?

To maintain the ideal temperature inside your home, the compressor start relay goes on and off during the cooling cycle. Without the start relay, the compressor won’t be connected and there won’t be any power to the AC unit.

What are the symptoms of a bad AC relay?

Due to a bad AC relay, the compressor of the AC won’t turn on. More so, there won’t be any cold air. You may also notice inconsistent cooling too.

How much does it cost to fix a stuck AC relay?

Depending on whether you have a blown fuse or bad AC relay, it may cost you around $20 to $400.

What causes AC relay failure?

Lots of factors may lead to AC relay switch failures like faulty control switch, low refrigerant, or faulty pressure switch.

How do I know if my compressor relay is bad?

You can apply the shake and rattle test to know whether you have a bad compressor relay. Just unplug the start relay and shake it. If you can hear any rattling sound from the inside, you need to replace the start relay.

Final Words 

Well, there you go. Now you know how to fix a stuck relay on the AC unit. One thing you should keep in mind is that no matter what you do over time the relay will break down at some point.

There is no roundabout way to that. It’s best to opt for a professional technician if you have no idea of this thing. But with my guide and your little experience in electrical work you can do it pretty easily.

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4 thoughts on “How To Fix A Stuck Relay On AC Unit In A Step By Step Way Like A PRO?”

  1. My ac fan don’t stop working even if I put the ac on the off position even with the ac fuse in the off position. I replaced the relay but it is the same result

  2. My RV rooftop AC had issues kicking in the compressor, possibly worn compressor. However after replacing all three capacitors, only when I replace the last one for the compressor start or run, did the compressor and cooling return. But now as before when the AC operates, it seems the thermostat cannot turn off the compressor and fan. I suspect the control switch or the start run relay is responsible. Without any guidance, I’m hesitant to replace the start run relay because the terminals aren’t marked on the replacement relay and as such I don’t understand the graphics alone on the new relay. Trying to determine if the main control switch might be the issue in commanding the thermostat’s off function. Any advice appreciated.

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