Brake Lights not working

I apologize in advance, I know this has probably been addressed a million times, but I did a search and can't find any solutions that I haven't already tried.

I have a 2003 Tacoma, 4x4, Got home last night and none of my brake lights are working. I checked all the fuses, replaced the brake switch, relay and bulbs and nothing. I disconnected the wiring harness for trailer lights thinking that might be the cause and they still don't work.

To top it off, the 3rd brake light now flashes when the hazards are on and the actual rear hazards are super dim. At one point when I would turn the turn signals on in either direction all of the rear lights would flash like it was a construction safety vehicle, including the left license plate light.

I thought that perhaps the bulb sockets were corroded and had some junk in there, so I pulled all the bulbs on both sides, tried the lights again. This caused the turn signals to work properly now but the 3rd brake light was still blinking with them.

The head lights and front turn signals work fine, the reverse and parking lights also work as they should.

I know it has to be something electrical, but I'm at my wits end trying to determine what it actually is. I don't want to take it to a dealer, but I'm about to that point. Any suggestions would be awesome.

Thanks in advance!

 

not that familiar with our tail lights but if it has a circuit board it might be shorted. try unplugging both tail lights then try one at a time but not both together, if one is shorted you will know which it is.

only other thoughts is most times problems like this are from bad grounds so check those connections and maybe try running a new wire to a solid good ground just to see.

 

Awesome, I will try that tonight when I get home. Thanks!

 

I'll bet $100 its the plugs for the tail lights. They corrode very easily. I had this problem a few weeks ago and it took the better half of a day to trace wires back to each tail light. All I can say is good luck. Have a good multi meter and start stabing wires.

The feed for the passenger side tail light goes in through the drivers side, back out then crosses over to the passenger side

 

How did you go about fixing it? Did you replace the wires and plugs?

 

Yup, replaced all the wire ends that were corroded. By passed the electrical plugs and heat shrinked everything. Their all water tight now

 

Do you know if they just make new plugs that I an wire on? If so where can I buy those? Sorry for all the questions, I'm not electrically inclined at all.

 

Yes Toyota does. I called about it, but they have to be soldered on. Which is a pain in the ass. Every wire has to be sniped and re soldered into its plug. Your better off finding out which wire(s) are giving you trouble, snip them and wire them straight across to the tail light (bypass the white electrical plug). My guess is it's your running lights that are giving you trouble as they use they same bulb for brake and running lights.

 

TLDR:
My issue - both rear brake lights out, but 3rd brake light worked.
Problem was broken wire junction where trailer lights were wired
into harness at rear bumper. Fixed this connection and problem solved.

Long winded description:
This is a great site. Am posting this as "payback" for the many
times I've used the info here. Apologies if this is posted in the wrong
place.

Issue: 2003 Tacoma with TRD & shell. Both rear stop lights not functioning.
All other rear lights working.

Checked: Fuse - OK
Bulbs - OK, and no power being supplied.
Switch - Under dash, near brake pedal. Took it out
and tested. Seemed bad, but was actually OK. This
switch serves both brake lights and Cruise control
cut off. It turns one on, and the other off.
Replaced switch - about $35 and in stock at O'Reiley. Dealer
wanted $80 !!!, and not in stock.
Upshot was that switch was fine and now I have two of them.
3rd brake light - OK
I should have checked this earlier, but it is hidden
by my shell. If this works it indicates problem likely
with wiring harness.

Checked wiring harness running along left (drivers side) side frame
member. Looked OK, but there was a real rats nest of wires
where UHaul trailer wiring was attached to harness near
rear bumper. I bought this truck used, previous owner(s) must have
had this work done.

Washed off mud under truck (not really needed).

Looked up wiring diagram in 2003_FSM.zip. It says
in rear harness:
Ground is white with black stripe
Stop is green with white stripe
Backup is red with black stripe
Left turn is green with blue stripe
Right turn is green with yellow stripe
Tail & plate lights is green

Started investigating rats nest of wires. Sure enough
there was one completely lose one, green and white (I think)
that showed 12 volts when brake pedal depressed.
Tested with voltmeter, and using a hiking pole to
hold brake pedal down while I was using voltmeter.

Fix: Found location where wire had broken off. Reattached
with a little solder (hard due to awkward location),
a screw on wire connector,
and electrical tape. Cleaned up the rats nest a bit with
electrical tape and zip ties. Tried to make sure that
any motion was limited and truck bouncing would not weight
any electrical connections. Still not as solid as a stock
harness (with no trailer wiring) would be.

Test: All lights working - Miller time - never again

 

Just a old thread!!
You would have been better to start a new one