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A/C Light Flashing and No Cold Air

It’s an inevitable issue on early model 4th generation Toyota 4Runners: the A/C Light suddenly starts flashing or blinking and the cold air coming from your vents suddenly becomes warm. This happens to almost all of us 4th gen 4Runner owners; it’s happened to me around the time I bought my car more than 7 years ago, and it happened to me again recently.

What you might notice is that when you turn on your car again, the air conditioning might work for a short amount of time again. However, soon after the a/c light will begin intermittently flashing and the air conditioner stops working.

The issue is typically not that the air conditioner system has failed, but simply an electrical relay that was destined to fail over time. This magnetic clutch relay is located in the fuse box located under the hood. This relay will need to be replaced in order for the a/c light flashing issue to be resolved.

Tools/Materials

Long-nose Pliers

Long-nose pliers are my tool of choice for removing and installing fuses/relays. They work perfectly for getting in between other fuses/relays and they allow you to get a firm grip for both removing and installing. They’re great for either size: the smaller fuses, or even the larger relays.

Find at: Amazon

Magnetic Clutch Relay

This relay is the one that fails under the use of the A/C system. The problem doesn’t only plague early model 4th gen 4Runners, but other Toyota models as well. There is actually a Technical Service Bulletin (EL011-05) issued by Toyota that specifically addresses this issue.

The part number for the relay that comes with the car is 90987-02022 (white in color). The TSB that Toyota provides guidance on this issue states that a replacement relay part number 90987-02028 shall be used.

You can either find an OEM relay (90987-02028) at your local Toyota Dealership or online, but they will cost somewhere between $30-$60 depending on where you get it. Personally, I purchase aftermarket ones on Amazon and they hold up pretty well. These are the ones I have purchased in the past for my 4Runner:

Four Seasons 35874 Standard Relay
2 Pack AC Relay Compatible with 1997-2014 Toyota Lexus and Scion Vehicles

How to Replace A/C Magnetic Clutch Relay

This is pretty straightforward, just replace the relay. Open the hood, find and open the fuse box.

Using the fuse diagram on the cover of the fuse box, locate the relay labeled as ‘MG CLT‘. This is the magnetic clutch relay for the A/C. Remove this with long-nose pliers.

Some people (including myself) have mistakenly replaced the ‘AC 115V’ relay, which will not work. Make sure you replace the ‘MG CLT’ relay in order for this fix to work.

4runner 4th ac light flashing - relay replacement

At this point, if you’re in a pinch and need to have your A/C working right away, or if you just want the A/C working until your replacement part comes in, you can simply swap with one of the other relays (with same part number 90987-02022) for the interim. There’s several other relays that you can use, but many of these perform more significant functions. A safe option to swap with is #2, FR FOG. This relay is related to the front fog lights and is probably the safest option if you want to swap the relays for the time being.

If you plan to replace the relay (90987-02022) and have the new replacement relay on-hand (90987-02028), then it’s just simply a matter of removing the old fuse and inserting the new fuse.

Now go start the car, and test out the air conditioning to see verify that the problem has been resolved.

4runner 4th ac light flashing - ac fixed
Author

Hi there! I'm Scott and I run The Track Ahead. My goal is to write helpful articles, tutorials, and reviews based on my personal experience with car maintenance and detailing. I've been wrenching on and detailing cars for 15+ years and now share my knowledge with others on this site to help them care for their vehicles.

12 Comments

  1. Great post and very descriptive w pics. One correction: the relay labeled “MG CLT” is the magnetic clutch relay. The “AC115V INV” is the space below the “MG CLT” and is for models that have an AC outlet in the center console. Your pics for the location are accurate. If readers follow this they will be successful. Thank for all of the help:)

    • Dave, thank you very much for the correction. I made the update on my post for future reference.

  2. B Guilfoyle Reply

    You are referencing the wrong relay. The correct relay is labeled “MG CLT” for the Air Conditioning Magnetic Clutch. The “AC 115V INV” is for the 115Volt AC inverter option.

    • Thank you, that was just brought to my attention and I made the correction to my post. My apologies for the mix-up.

  3. Rhonda Crosby Reply

    hello! I replaced the fuse and it’s colder and stopped the blinking!!! But….it started back again! It’s working longer than before. So what else could it be???

    • Hi, did you replace the relay with another one from your fuse box? Or did you buy a new one to use?

  4. Thank you Scott, your post on the relay on my 4runner to fix my air conditioner relay was just what I needed. Especially the detail and pictures and the suggestion to test it with the fog light relay. Thank you thank you.

  5. Hi. I have the same issue and replaced the relay with a new one 02028 and it worked for few hours and it’s doing the same thing. (I tried a 2nd new relay) but it’s the same results. Any ideas?

    • So just to confirm, you replaced the relay with a new 02028 relay and then the a/c worked for a few hours. Then the a/c light started flashing again, and then you replaced it with another 02028 relay, and it worked for another few hours, and then it stopped working again?

  6. What is the likely cause if I tried to AC 115 with the with Four Seasons Relay 35874 fuse, but it is still blowing hot air and the ac light is blinking. Did I replace the correct part?

    • I’ve made that mistake before… as I thought “AC 115V” stood for Air Conditioning. However, that is the wrong relay. You need to replace the ‘MG CLT’ relay in order for this fix to work. Good luck!

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