Tail lights not working...???

Just noticed that the tail lights aren't working on the '06 4door short bed Tacoma. Headlights, fog-lights, turn signals, brake lights are just fine.
This truck also has automatic headlight shutoff, whereas the headlight stay on when the engine is shut down then go off when the door is opened. That feature doesn't work correctly anymore. When the headlight switch is in the 'on' position and the engine is turned off, the headlights now go off even if the switch is in the 'on' position and the door is closed.
I checked al all fuses appear to be functioning as required. At least none are burned out. Might there be a switch I don't know about?
Any idea what's going on??

 

just curious if any electrical work has been done to your truck recently? Or if you added trailer lights, etc.? Or did this start happening to a stock truck?

 

I installed a trailer hitch and wiring kit last year. I also installed a back-up alarm about a month ago.
The trailer I occasionally tow is a very small aluminum trailer converted to a flat bed with expanded metal flooring instead of wood. I re-did the entire wiring on that when I refurbished it last year.
One thing of interest is that I didn't notice the lights on the truck not working until I connected in the trailer and the truck connectors. Not to say that they were or weren't working before he plugs were connected, just that I never noticed.

 

Which wiring harness did you use? Did it come with the "black box" module? I would try removing the trailer harness and see if your lights function normal.

 

It'a CURT hitch and wiring kit that does include the "black box" module. I'll give that a try later.
If that's the issue, what would be a solution? Another wiring kit? Any specific brand better than others?
When I get to that project, I'll take a look at all the connectors inside the Tacoma rear light area to be sure they're all intact. I tend to not scrimp when it comes to wiring. With 12V, I use Posi-lock connectors: http://www.posi-lock.com/

 

I used a T connector after market trailer hook up with a 'black box' type thing, but after a few months it stopped working properly. Didn't loose tail lights, but they started working strangely and warning lights lit up on the dash for check engine and abs. Bit the bullet and got the Toyota OEM kit. No problems.

 

I see what you meant about 'bite the bullet'. That harness from Toyota is $95.00 in my area.
Anyway, speaking to service, they suggest I isolate the trailer wiring and see if that makes a difference. I'll do that and if the existing harness is an issue, I may bite the bullet too.

More to follow if I find out anything.

 

I bypassed the Curt hitch wiring and nothing has changed. Any ideas?

 

your body ecu may have gone bad. Happened to me in an '01 Highlander. Same symptoms.

it's an expensive part.

 

You could try checking every fuse and relay - both in box under the hood and in the cab - even if you don't think a particular circuit has to do with tail lights, it might. ABS and a couple of other things (odometer display that I noticed flashing off and on) are tied into the lights.

I found also that if the lights malfunctioned, (after turning on the 4 way flashers for example) they would 'refresh' themselves somehow, so maybe try disconnecting the battery for a while?

I also remember reading about a year that had some fuses near the back bumper, but did not apply to mine (09) so can't remember much about that.

 

Still no solutions to 'why' the fuse burned out but the problem has been fixed. Found a burnt fuse for 'tail light' in the cab fuse holder and replaced it. All is well with the truck.
Sprayed both truck and trailer connectors with copious amounts of WD40 to dry out any moisture and when I plugged them together all lights work and have since.
Might have been a wet connector that shorted out due to water inside the plugs so I'll be alert for that each time I plug them together.
Other than that <shrug>.

 

There might not have been a wiring short in the usual sense. You may have had a combination of things that "back channelled" electrical current - current flowing in reverse to complete another circuit.