Defroster not working - Toyota 4Runner Forum

Sifrk · 12-10-2019, 09:31 PM

Hey!
So I just found out my defroster isn't working. The button on the center console isn't even lighting up. I checked the fuse box in the engine bay. The 30AMP fuse under 'DEF' was fine, and the large square-ish fuse(?) didn't appear to be damaged. I haven't taken out the plastic in the center console yet, so maybe there's a loose connection? Any ideas?

Dillusion · 12-10-2019, 09:53 PM

Bad switch?

Think the squareish fuse you are referring to is a relay.

Can try to swap the relay with another one and see if it works. if not try to by pass the switch.

Sifrk · 12-10-2019, 10:05 PM

Quote:

Originally Posted by Dillusion

Bad switch?

Think the squareish fuse you are referring to is a relay.

Can try to swap the relay with another one and see if it works. if not try to by pass the switch.

I tried swapping the relay but no luck either. BTW, the night light does come on so there's power to the button.

How do I bypass the switch?

Dillusion · 12-11-2019, 01:27 PM

Quote:

Originally Posted by Sifrk

I tried swapping the relay but no luck either. BTW, the night light does come on so there's power to the button.

How do I bypass the switch?

Pull it off guessing the dash trim needs to come off and I'm assuming it is normally open. Just manually short out the wires.

If that doesn't work need to find a wiring diagram and see where you are losing the power.

Sifrk · 12-11-2019, 05:29 PM

Quote:

Originally Posted by Dillusion

Pull it off guessing the dash trim needs to come off and I'm assuming it is normally open. Just manually short out the wires.

If that doesn't work need to find a wiring diagram and see where you are losing the power.

I've had the dash off before, but usually any wiring will be attached to a harness. I'll give it a shot anyway. Thanks!

Dillusion · 12-11-2019, 05:55 PM

Quote:

Originally Posted by Sifrk

I've had the dash off before, but usually any wiring will be attached to a harness. I'll give it a shot anyway. Thanks!

I've never pulled mine apart but I have to guess that behind the switch should have a plug when you can short the pins when removed.

Sifrk · 12-11-2019, 09:36 PM

Quote:

Originally Posted by Dillusion

I've never pulled mine apart but I have to guess that behind the switch should have a plug when you can short the pins when removed.

I'll keep you posted. Probably not going to tackle that till the weekend. I'm surprised I didn't just find a blown fuse. Hate troubleshooting

El Dusty · 12-12-2019, 01:28 AM

Quote:

Originally Posted by Sifrk

I'll keep you posted. Probably not going to tackle that till the weekend. I'm surprised I didn't just find a blown fuse. Hate troubleshooting

Might sound silly but check that the rear window is rolled up all the way. I believe there is a sensor in the rear window system that stops the defrost circuit. You can easily test the sensor here as the rear window wiper will only run if this sensor is working with the window rolled up. Best of luck.

Sifrk · 12-12-2019, 07:38 PM

Quote:

Originally Posted by El Dusty

Might sound silly but check that the rear window is rolled up all the way. I believe there is a sensor in the rear window system that stops the defrost circuit. You can easily test the sensor here as the rear window wiper will only run if this sensor is working with the window rolled up. Best of luck.

Sounded silly but that was the fix. Holy crap! I guess that fail safe makes sense??? IDK. Anyway, thanks man!

nb rob · 12-19-2019, 06:38 PM

that's a weekly thread in the 5th gen section.

Glad you got it to the bottom of it! Free fixes are the best

Sifrk · 12-19-2019, 09:45 PM

Quote:

Originally Posted by nb rob

that's a weekly thread in the 5th gen section.

Glad you got it to the bottom of it! Free fixes are the best

Absolutely! Glad the community is willing to help.

I get the reason for the safeguard, but man! an indicator light would be appreciated, Toyota.

Osborne White · 01-06-2020, 10:59 PM

I was really relieved to read this thread...Last week during a hard rain I realized my rear wiper didn't work and while investigating I noted that the rear defroster didn't work and no indicator light..I went to the fuse box and checked the fuses all good..(still don't know where to find a wiring diagram)..I was lost..thought I would try the rear window to see if that worked..was it on the same circuit..rear window worked fine...on the drive home from work the next day I thought I would try the defroster again and MAGIC ......everything worked. Now I know how I fixed my problem....THANK YOU EL Dusty and forum members.

KDubb · 01-28-2020, 07:29 PM

Quote:

Originally Posted by El Dusty

Might sound silly but check that the rear window is rolled up all the way. I believe there is a sensor in the rear window system that stops the defrost circuit. You can easily test the sensor here as the rear window wiper will only run if this sensor is working with the window rolled up. Best of luck.

I will keep this in mind. My dog loves to lolly gag out that window so it goes up and down a lot.

Vegg8 · 01-07-2022, 05:10 PM

Quote:

Originally Posted by El Dusty

Might sound silly but check that the rear window is rolled up all the way. I believe there is a sensor in the rear window system that stops the defrost circuit. You can easily test the sensor here as the rear window wiper will only run if this sensor is working with the window rolled up. Best of luck.

Had the same problem. defroster not working, back window wiper not working. Tried to roll down window then roll it up which fixed the issue.

TRD88 · 01-08-2022, 02:51 PM

For those that don’t know, you can disable the rear window by locking all the windows with the window lockout switch located on the drivers door. However, it would be nice to simply lockout the switch on the center console without having to disable all the windows. Does anyone make something that clips onto the rear window center console switch that prevents the switch from accidentally/unknowingly being activated?

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