I have a perplexing issue and would really appreciate your help!

The tail lights (both sides) on my 2007 4Runner are not working but all brake lights are working:

- Headlights work
- Turn signals work
- Reverse lights work
- Brake lights work
- Tail lights DO NOT work
- License plate lights DO NOT work
- Instrument cluster lights work

I plugged new bulbs (#7443) into the wiring connectors and the same issues so I think the (LED) tail light assembly can be ruled out. I also plugged new light bulbs into the license plate lights and they still did not work.

I tested the fuses with a circuit test light and found the following:

- 10A STOP fuse (under the hood) appears to be good. (See pic)
- 10A TAIL fuse under the dash does NOT appear to be good, but replaced with another (good) fuse and it still did not work. (See pic)
- The contacts under the fuse (with fuse removed) are NOT working either (see pic)

I'm not sure why the instrument panel lights are working since it appears to run through this fuse? (See pic of fuse items #43).

Any ideas of what I can check next or mistakes I've made so far?

I really need to get this figured out so my son can drive this at night without getting run in to.

Thanks in advance for your help!

 

I'm not familiar with the 2007 but here are some things that come to mind.
are you checking both sides of the fuses or just the one point you show in your picture?
do you have the ignition turned on or the headlights on when testing the fuses?
do you have trailer wiring?
Check ALL of the fuses under the hood, like the one labeled "Towing"

 

Hi,

Yes, I tried both sides of the fuse with the test light, and I did have both the engine running and lights turned on. I do have trailer wiring that leads to the receiver hitch area.

I may not have tried all the fuses under the hood, so I will be sure to do that and check the Towing fuse and report back.

I was wondering if the lights/turn signal control switch on the steering column could be bad and causing an issue with the tail lights (although the headlights work)? Is the lights/blinkers control switch "downstream" of the fuse box though or could that affect the fuse?

Also, I'm wondering if the fuse I'm questioning (TAIL 10A ) located in the interior of the 4runner could really be the issue since the instrument panel lights are working and that is supposedly one of the items on that fuse (see list below):

43. TAIL 10 A: Tail lights, license plate
lights, parking lights, instrument panel
light control, multiport fuel injection
system/sequential multiport fuel injection
system, instrument panel lights,
meter and gauge, glove box light

Thank you and to all who can try and assist me!

 

the fuses should "feed" the switch so if there is a short the fuse will protect the circuit to keep your vehicle from burning to the ground.
your switch could be bad, but more likely there was a short in your trailer wiring that popped the fuse.
always start with the simple stuff, check EVERY fuse first, replace any that are blown and test the lights to see if they blow again. if they do you need to find and fix the short which can be complicated.
It could also be a short in the wiring on the last trailer that was towed.

 

I guess I should clarify, the underhood fuse should feed the switch, the dash fuse is likely to be on the output from the switch.

 

I ordered a new turn signal/light switch so I'll install that and see if that is the issue. I did check the rest of the fuses (under hood and interior) and nothing seems out of place except perhaps the fuse position #43 (tail lights). The actual fuse in that position is good but I'm not sure it's getting power to that fuse (although the instrument panel lights are working which is on that fuse?)

Any other idea in the meantime are appreciated.

Thanks

 

It's always better to get a wiring diagram first and diagnose the problem.
Firing the parts cannon gets expensive and frustrating.
In the pictures you attached it also shows fuel injection is powered by that fuse, so if you aren't seeing power there but the engine runs you are checking it wrong.

 

That is certainly wise advice...I will look for a wiring diagram (if anyone has a source it would be greatly appreciated). I will try the new light switch and then regroup after that.

thanks

 

Well, I tried a new headlight control switch (stalk) but it didn't solve the issue. I still have brake lights/turn signals/reverse lights but NO tail lights or parking lights.

I've tried bulbs, I've tested fuses and even replaced a 40A trailer fuse under the hood because I couldn't figure out how to test those square type ones. I still suspect an issue in the 10A tail fuse area (#43 position on the chart) in the interior fuse block (not the fuse itself which tests fine) but why would the instrument panel lights, fuel injection etc still work since it's on that fuse as well? When I take that fuse out and use the test light where the fuse plugs in it doesn't seem to have power.

Is there a tail light relay I can check or any other ideas?

Thanks

 

Get a wiring diagram!!!
Without that you will just get a bunch of guesses as to what it might be and you will just throw away more time and money on parts it doesn't need.
Plenty of folks will offer suggestions as to what it might be, but if you don't follow the circuit testing for power and ground it is all just guessing.
This is a snippet from the wiring diagram from my 1995 4runner, it surely will not match up to your 07 and it is only part of the circuit, but there is likely some resemblance.

 

It was the tail light relay which is hidden on the back of the interior fuse block assembly (but shown on the wiring diagram of course). The lower dash area had to be taken apart and the fuse box dropped in order to access it. Thanks again for your help and patience.