DIY: Tail Lamp Failure Sensor Bypass GET YOUR TAIL AND/OR BRAKE LIGHTS BACK!

[lewis15498]

I recently had a problem with my tail lamp failure sensor. Previous threads have commented on how much the sensor causes problems, but I couldnt find a thread explaining how to remove it instead of replacing it. I wasnt willing to shell out the extra $$ at the stealership, or risk getting the wrong sensor at the salvage yard, so here is my solution, I hope its helpful. Feel free to add anything I may have forgotten.

WARNING: This modification will disable the orange Tail Lamp Failure Warning Light on your dashboard. If this is unacceptable to you, you must purchase a replacement sensor. If you are not comfortable attempting this modification have someone who does do it. I will not be held responsible for any damage or bodily injury that is directly or indirectly a result of this modification. Proceed at your own risk.

1) Locate and remove sensor.
The sensor is located under the drivers tail light. Unclip it from the body and then unplug it.

2) Bypass the tail light circuit.
Connect the tail light signal wire (Green) to the tail light wire (Green w/ Red Stripe). I reccomend using wire tap in squeeze connectors that way you dont have to cut any wires.

3) Bypass the brake light circuit.
Connect the brakelight signal wire (Green w/ White Stripe) to the brake light wire (Red w/ Blue stripe) and the the 3rd brake light wire (Red w/ White Stripe). Again all three of these wires are to be connected together.

4) Throw away your broken Tail Lamp Failure Sensor
Do not plug your sensor back in. Doing so will cause the annoying orange lamp failure warning light on your dash to stay on. Leave it unplugged ant the light will stay off.

5) Test your work
Turn on your lights and make sure your tail lights work properly. Have a friend step on the brake pedal, and make sure your brake lights work properly as well. Dont forget to check the Third (spoiler) brake light.

Now you should have all your brake and tail lights back, no thanks to that stupid sensor. Everything should work as it did before your sensor failed, however now when a bulb blows out your dash warning light wont come on.

Best of luck.

 

[keo]

thanks, im going to try this cause im tired of looking at that orange lamp failure warning light.

 

[88-7MGTE]

When i drove my car the tail light signal would blink on pot holes, it appeared tat the tail was blinking at the same time what could be the problem? wiring in the tail light itself or wiring somewhere away from tails ?

 

[csr ma71]

I wish you had wrote this months ago when about cops kept on stopping me for having no tail light. All of them were cool with the exception of one from the rich folks neighborhood.

I also did the same rewire last week. Good stuff. My tail light failure box would work randomly if I jiggled the wires and pushed the plug into the box a certain way. After the rewire, no more jiggling required.

 

[tsuper92]

ahh,another local supra owner on the forum

hey keo,i just noticed you,csrma71, and me joined at the same time

 

[lewis15498]

88-7MGTE: sounds like you have a connection problem or a bad bulb.
1) visually inspect your tail light bulbs make sure the fillament isnt, broken but still touching
2) take out the tail lamp failure sensor. Check to see if any of the components on the board have visual damage or a bad connection. Ground yourself first as static electricity can damage some electrial components.
3) Check your wiring, make sure there are no broken or damaged wires. Since the warning light is turning on this means the wiring problem (if there is one) is in or after the tail lamp sensor. Check to make sure the plug is making good connection. Save you some time, the post sensor wires only run across the back of the car (with the exception of the third brake light wire) so you should only need to remove the rear interior panel.
4) If you cant find the problem you can always try the mod. Doing so wont hurt anything, but its nice to have the tail lamp sensor when it works properly.

Hope you get it sorted out

*When testing connections, or pretty much anything electrical a multimeter is an excellent tool to have. You can get them at any auto parts or electronics store ranging anywhere from $10-$100. I love my $60 radio shack unit, but you dont need anything that fancy. If you dont know how to use it take the time to read the manual that comes with it. Most have many features (including some i'll never use) and knowing what setting to use and how to use it makes all the difference. If your still unclear on how to use it, find someone who does, and is friendly enough to explain it to you in person.

CSR MA71: I know how you feel I wrote the write up literally 3 hours after I figured out how to do it, to avoid anyone else from suffering from this plague.

 

[Dr Chill]

i did this by-pass a few years ago & still have no issues ,
i never posted because its kinda ghetto but required , because the new SLFS I plugged in didnt work either.
i figured i'd add my 2 cents because of the lenght of time the by-pass has lasted with no issues

 

[Mikek3]

I actually just bought a new tail light failure sensor, wish this was up two weeks ago, was only twenty bucks and works fine so i guess its not too bad

 

[hvyman]

make sure you tail light gaskets are good water will destroy that box other than that good diy

 

[NgoFcukinWay]

Is the TLFS any way connected to the lights on the gauge cluster and the turn signals?

 

[Poodles]

turn signals and license plate lights aren't in the circuit IIRC...

Bad turn signals is either the relay or the hazard switch (if the hazard switch is disconnected turn signals don't work).

Also, many times the tail lamp failure box can be repaired...

 

[NgoFcukinWay]

Bad turn signals is either the relay or the hazard switch (if the hazard switch is disconnected turn signals don't work).

Oohh that explains it.

 

[Frankenstien]

I agree with Poodles, the tail light failure box can usually be fixed.
I've never done it myself but from what I've read the box can be taken apart and cleaned, or the broken connections inside repaired.

 

[IndyMK3]

I may have to do this mod... i have no tail lights...at all but i have brake lights, turn signals, and reverse lights... but no rear side markers, tails, or license plate lights.... i took apart the light failure box and looks like there is a burned wire on the circuit board... i got another out of a 87 (mines and 88) and i have the same problem... so that makes me to believe that its in the wiring that leads up to the front of the car.

 

[Doward]

Guys keep in mind, the taillight box works on resistance. If you've got corrosion on your bulb sockets, the box will keep thinking one of the bulbs in blown.

Clean ALL contacts thoroughly.

 

[87soup]

Ok.. I had no tail lights or brake lights so i did the mod and now i have no dash or parking lights as well...

What happened???
Please help, im scared of getting pulled over:cry:

 

[RazoE]

My recent one went out, took it apart, resoldered one contact, and it's been fine since.

I've gone through atleast 7 boxes, including the blue Supra.

 

[87soup]

Is this wrong????
My dash/ parking lights dont work any more and i keep popping my 15amp gauge fuse...
Also STILL NO TAIL LIGHTS!!!!
PLEASE HELP!!!!

 

[87soup]

Anyone???

Can someone take pics of the TLFS elimination????

 

[RazoE]

The way I had mine connected was..

solid green wire with the green/red wire

red/blue wire with green/white

I did lose my 3rd brake light, but that takes a back seat to functioning taillights..