How JustAnswer Works:
  • Ask an Expert
    Experts are full of valuable knowledge and are ready to help with any question. Credentials confirmed by a Fortune 500 verification firm.
  • Get a Professional Answer
    Via email, text message, or notification as you wait on our site.
    Ask follow up questions if you need to.
  • 100% Satisfaction Guarantee
    Rate the answer you receive.
Ask Skyvisions Your Own Question
Skyvisions, ASE Certified Technician
Category: Toyota
Satisfied Customers: 14417
Experience:  Toyota Master Diagnostic
Type Your Toyota Question Here...
Skyvisions is online now
A new question is answered every 9 seconds

Hello, I have a 2004 Highlander with a tail light problem.

This answer was rated:

I have a 2004 Highlander with a tail light problem. My rear running lights don't work, although the break, turn, and hazard lights work fine. I don't know if it's a fuse or the relay. I must be getting 12v to the back lights or the break etc wouldn't work. I suspect the relay, I would think the realy would turn of both the front lamps and rear running lights, and the head lights work fine - Just the rear running lights are hosed.

Any tips to diagnose the problem would be appreciated.

Do the front marker lights or the license plate lights work? Do the dash lights illuminate?

Have you tried new bulbs?



Customer: replied 7 years ago.

I edited the reply slightly, it wasn't very readable - Sorry.

Thanks, XXXXX XXXXX closer inspection the front marker lights don't work either. The light switch has two positions the first, I assume is for the running/marker lights and the other is for the headlights. The first position doesn't actuate anything as far as I can tell. When the head lights actuate I can hear the relay but not on position one. Could it be that the relay has two switches and first has failed? It didn't think relays failed that much.

Also, the dash lights are fine.

I don't see the license plate light either.


Thanks again

The information that you have explained above is correct. First notch on the switch is for the interior illumination lights for the controls and for the tail lights and the front running lights. The tail light relay is on the back side of the lower finish panel junction block. This is the fuse box behind the coin tray that holds that fuses by the drivers knees. You should be able to hear this relay click or feel it click by reaching up under the lower side of the dash on the drivers side. Make sure that you have checked the tail light fuse and the panel fuse in this fuse box. If all of the fuses check okay and this relay is not clicking you'll need to do further testing of the relay and the power supply going to it. This will require some test equipment on your part and I can walk you through some electrical test if you are up to the task. If you have a volt meter or a 12 V test light we need to determine if there is even power at the tail light fuse. Let me know how you would like to perceive



Customer: replied 7 years ago.

Hey thanks.

Here what I've done:

Found the fuse, thanks. XXXXX again! So I've got a short somewhere ..Right? I thought about removing the connectors to the rear lights, test, then the front then test. At least I can tell what light is failing. The front lights are cloudy - I'm thinking it's them. Any idea what would cause a short ?- If I'd blown a blub I'd think it would be an open circuit.

I've got a volt meter around somewhere but I'm having trouble finding it...I think this plan will work in a pinch -- Thoughts ?

The quickest way is to isolate the rear section of the wiring or taillights. Remove the left plastic kick panel by the drivers left foot. Behind this cover you will find all of the connectors that go to the wiring harness that feeds the rear taillights and most of the controls for the rear. Unplug these connectors that go to the rear then reinstall the fuse and turn the taillights which on and see if the fuse pops. If it does then you know the short has to be in the illumination system or more probably in the running lights that go to the front of the vehicle. If this vehicle is equipped with a towing package with a trailer wiring harness plug in the rear that is the most common problem for causing shorts in the taillights circuit I would check that first. Let me know what you find. I would definitely check all of the bulbs. Normally when a ball blows out it blows a circuit open you are correct. But in some cases I have seen the filaments melt or bend over in short to ground.



Customer: replied 7 years ago.

Thanks, I'm working on it this morning and I let you know what I find. And, it does have a towing package.


Let me know and pay particular attention to the controller/box and plug for the trailer wiring.



Skyvisions and 2 other Toyota Specialists are ready to help you
Customer: replied 7 years ago.

Thanks for your help. It was a rear amber tail light that was shorting.


All Fixed !

Congratulations! You got an education and you saved a bunch of money and you didn't have to switch to Geico insurance :) if you need anything in the future just ask for me in the question and I'll get back to you.