I think my Corolla blew a fuse

[brikis98]

I installed a new car stereo this weekend and for 2 days, everything worked great. Then, last night, the lights on my dash suddenly went out. That is, my speedometer and odometer are no longer illuminated; however, all the other lights, even the warning lights around the dash, work just fine, including blinkers, check engine light, seatbelt light, door open indicator, dome light, headlights, etc. So it's almost as if I had turned my dimmer all the way down, but I checked, and it's definitely not.

I took the stereo out and noticed that there was a loose wire: the Toyota adapter harness I was using has a "dimmer" wire (orange/white stripe) but the stereo had no matching wire and I must have missed it. The wire was exposed (the harness wires are pre-crimped) and my guess is that it caused a short and blue out a fuse. I taped the wire up with electrical tape but, not surprisingly, I still have no lights in the dash.

As shown on this page, the Corolla has two fuseboxes. Which fuses do I need to check and how do I know if they are blown or not (I'm fairly limited on tools)?


Update: it was NOT the dimmer!

I was googling around and ran across a thread that mentioned that the Corolla's dashboard lighting, for whatever reason, was on the same fuse as the tail lights (talk about unintuitive). I checked out the fuse labeled "TAIL" and, sure enough, it was blown. I replaced it with a spare fuse and voila, problem solved! So, the good news is that this repair cost me nothing. The bad news is that for the 5 minute drive home I had last night after the fuse blew, my tail lights must have been off. When I stepped on the break they would turn on (I checked this morning) but during normal night driving, I must have been tough to spot from behind. Pretty dangerous, but I was fortunately close to home when it happened, and it's all fixed now.

Thanks for the help everyone

 

[SearchMaster]

Are you sure that's not the dimmer itself and not a fuse? What about the "gauge" fuse - have you checked that one?

 

[brikis98]

Originally posted by: SearchMaster
Are you sure that's not the dimmer itself and not a fuse?

I suppose the dimmer itself could've shorted out, but I thought the fuses were there to prevent that? At any rate, I can't seem to get the dimmer fuse out, so I'm not sure how to check it.

Originally posted by: SearchMaster
What about the "gauge" fuse - have you checked that one?

I'll check it out in a little while.

 

[LTC8K6]

There's a fuse puller in that picture...

 

[brikis98]

Originally posted by: LTC8K6
There's a fuse puller in that picture...

Where? And does it work on that big gray cube type fuse?

 

[brikis98]

Originally posted by: brikis98

Originally posted by: LTC8K6
There's a fuse puller in that picture...

Where? And does it work on that big gray cube type fuse?

Er, ok, pardon my stupidity. I found the fuse puller and used it to check the guage fuse which visually looks just fine. I then took a closer look at the dimmer fuse... and realized it's not a fuse at all. It's 12V relay. Could a relay short out?

Edit ---> This relay has the exact same OEM part number (90080-87024): Duralast Relay and looks exactly like the dimmer relay in my fuse box.

 

[LTC8K6]

It looks like you have more than 1 of those relays. Maybe swap them? I think I see another one far left.

 

[brikis98]

Originally posted by: LTC8K6
It looks like you have more than 1 of those relays. Maybe swap them? I think I see another one far left.

Good idea, but how the heck do I get them out? I pull fairly hard on it and it wouldn't come out... I'm not sure if there is some trick to it and I don't want to break anything (else) to find out...

 

[LTC8K6]

They usually just pull out, but there could be some sort of tab or hold down that you need to release.

I would think that if you shorted out your dimmer, the problem would be with the reostat itself, aka the brightness control.

Do they come on if you turn them all the way up? Not sure if you have the type of dimmer that clicks in the full on position...

 

[brikis98]

Originally posted by: LTC8K6
They usually just pull out, but there could be some sort of tab or hold down that you need to release.

I guess I'll have to try again as I had no success the first time.

Originally posted by: LTC8K6
I would think that if you shorted out your dimmer, the problem would be with the reostat itself, aka the brightness control.

Any way to test that theory? Is there a way to unhook the dimmer and just hook up the lights "directly" so they are full on? And if not, how hard/expensive is it to replace the dimmer?

Originally posted by: LTC8K6
Do they come on if you turn them all the way up? Not sure if you have the type of dimmer that clicks in the full on position...

The dimmer is just a round wheel that rotates up and down. Turning it all the way up/down has no effect right now.

 

[CurseTheSky]

Relays can be a pain to get out. I usually use my index finger and thumb and just pull / rock them back and forth until they pop out. My fingers are usually sore after pulling a few.

You can bench test a relay with a 12v source by shorting some of the pins IIRC, but it can be somewhat dangerous (no more dangerous than doing anything else with a car battery) and you'll need to find a guide for the relay online somewhere. If any of the relays are the same, you can just swap them around to see if any are dead. Relays should make a click with they engage.

 

[brikis98]

Update: I was finally able to get the dimmer relay out (with the help of some pliers) and swapped in the relay labeled "HEAD" (headlights?) which is the exact same model number. The dash lights still didn't work, so I think LTC8K6 might be right: the actual rheostat (dimmer) might be busted.

So, some new questions: is there any way to connect the in dash lights without the dimmer (to see if the dimmer is really the issue)? How hard/expensive is it to replace the dimmer?

 

[JulesMaximus]

You should have sprung for the Adam Corolla.

 

[LTC8K6]

Some dimmers will click when they are full on. This basically bypasses the dimmer part. That's what I was getting at as a test.

Go to Rock Auto to get an idea of dimmer switch costs.

Looks like anywhere from 50-150 depending on the exact Corolla and switch. Assuming it's an 05 Corolla.

 

[herrjimbo]

Originally posted by: brikis98
Update: I was finally able to get the dimmer relay out (with the help of some pliers) and swapped in the relay labeled "HEAD" (headlights?) which is the exact same model number. The dash lights still didn't work, so I think LTC8K6 might be right: the actual rheostat (dimmer) might be busted.

So, some new questions: is there any way to connect the in dash lights without the dimmer (to see if the dimmer is really the issue)? How hard/expensive is it to replace the dimmer?

there should be 2 main wires going to the dimmer. strip a little off the wires and connect the 2 with another wire. i did that to one of my cars years back and i had full illumination.

check for dimmers on ebay if it's too bright. it was good enough for me just crossing the wires.

just checked and there is a recall for the 2005 corolla dimmer switch. check into it. toyota may replace it for free.

 

[LTC8K6]

I think his dimmer is part of the multifunction switch...

 

[brikis98]

Update: it was NOT the dimmer!

I was googling around and ran across a thread that mentioned that the Corolla's dashboard lighting, for whatever reason, was on the same fuse as the tail lights (talk about unintuitive). I checked out the fuse labeled "TAIL" and, sure enough, it was blown. I replaced it with a spare fuse and voila, problem solved! So, the good news is that this repair cost me nothing. The bad news is that for the 5 minute drive home I had last night after the fuse blew, my tail lights must have been off. When I stepped on the break they would turn on (I checked this morning) but during normal night driving, I must have been tough to spot from behind. Pretty dangerous, but I was fortunately close to home when it happened, and it's all fixed now.

Thanks for the help everyone

 

[LTC8K6]

Glad you got it solved.

 

[SearchMaster]

That is a strange circuit, but I guess it would allow to easily notice that your tail light fuse was out since your gauges didn't work either. Glad you got it solved, and cheaply!

 

[scott916]

That happened to me once, too. It was just the lights on the speedo/tach/gauge cluster, and I got pulled over and they said my tail lights were out as well.

 

[LTC8K6]

Originally posted by: SearchMaster
That is a strange circuit, but I guess it would allow to easily notice that your tail light fuse was out since your gauges didn't work either. Glad you got it solved, and cheaply!

Yeah, I never would have thought they'd be on the same fuse...