Toyota Tail Lamp Failure Sensor Module Modification to Work With LED Taillights

Discussion in 'The Projects Forum' started by DrTom, Mar 21, 2013.

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  1. DrTom

    Thread Starter New Member

    Mar 21, 2013
    Hi guys. First, thank you for allowing me to post my question on this forums. I appreciate any help you guys can give me.

    Let me start by saying that I have limited knowledge of circuits and electronics. I work as a physician, and as such I only have undergraduate level general physics as my electronics background, so this is probably a very basic question.

    I converted a MKIV 1995 Toyota Supra's taillights from the standard halogen to a series of LEDs. The Supra has a taillamp failure sensor which illuminates a dash light telling you the taillights are out. As you might have figured out, it doesn't like the LEDs. I was hoping for some help to modify it to work correctly with the LEDs.

    Here's some information I found from another website

    Here are the circuit diagrams from the service manual:
    For taillights (on when headlights are on)
    For Stoplights (brake lights)
    and some pictures of the device itself:
    Clearly someone has swapped out the resistors. Originally the car used 1156 bulbs which are 19watt and have a resistance of 2.2ohms each, and half of the tail circuit (2 1156 bulbs running in parallel) has 1.3ohms resistance (as measured by the harness I have). It originally used a 2700k resistor in the circuit and a 6200k resistor in the other circuit for the brake lights.

    Thanks again for your help. You may have to dumb-down your answers a little for me. If anyone has any medical questions, weird bloodwork, or rashs/bumps you want someone to look at, I'm your man! That stuff is easy, electronics just seems to elude me.
  2. mcgyvr

    AAC Fanatic!

    Oct 15, 2009
    This board does not allow discussion of automotive modifications for safety reasons..
  3. Georacer


    Nov 25, 2009
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