Wanting to disable Tail Light warning light on dash

  • #1

    Wanting to disable Tail Light warning light on dash

    Now that I have my car running (engine at least) I would like to know if anyone might know how to disable the warning lamp that comes on if one or more of your tail lights/brake lights are not working. I know there is a tail light sensor in the rear of the car which detects a drop in current to the bulbs and somehow that makes the warning lamp come on. But guess what … if you replace the bulbs with nice high efficiency LED units, which draw much less amperage than stock bulbs, the car doesn't know the difference. Hence, the warning light comes on --- and stays on. It says on when the lights are on (at night) and each time you press the brake pedal (daytime). Maybe there's something that can be done with the sensor to fool it into thinking everything is fine? I'm not sure exactly how it works, or if removing it will simply fix the issue. (Doubtful)

    So, if anyone's done this, please let me know. Thank you.

    1985 GL 5-speed Turbo 2-seater Analog dash Federal emission
  • #2
    So basically you're saying to replace the sensor with straight wire? … taking it out of the circuit altogether?
  • #3
    Yeah I just jumped it with a few small pieces of wire and zip tied the jumped connector somewhere secure.
    http://z31performance.com/showthread…2-2-(-now-NA2T
    My build thread (:
  • #4
    Thank you all … consider it done!
  • #5
    Blue to blue, red to red
    It's too obvious
    http://z31performance.com/showthread…2-2-(-now-NA2T
    My build thread (:
  • #6
    Yes, I saw those in my shop manual (page EL-54). There are 6 wires total --- however won't just cutting the white wire (with blue trace) and taping it up (unconnected to prevent shorting to ground) work as well? It simply shows it to go directly to the dash warning lamp. It seems to me if that's where the bulb is getting its +12V (or ground) it will no longer light up … and everything else can remain the same (no jumpers needed).
  • #7
    .....And, on another note. My 86na has all LEDs, except dash, and works perfect.
    Gotta love Zs.

    86na
    88t
  • #8
    Do you have the sensor? … according to my manual, it's not in all versions of z31s.
  • #9
    My manual doesn't clarify which do or don't, just that there are two pages of tail light schematics --- one with the sensor and one without. So you may very well be correct about Canadian models. Anyway, I can only claim that up to model year 1985, after that, who knows?
  • #10
    After locating the sensor I decided to try just cutting the white with blue trace wire (which according to the FSM shows it going directly to the dash warning bulb). Bingo … it worked. I simply unwrapped the 6 wires coming out of the sensor past the plug, snipped the white with blue trace wire, and then taped the wires back together making sure the cut wire could not re-connect itself or touch ground. Then I reconnected the plug to the sensor. No need for jumpers using this fix, but you must reconnect the plug to the sensor, otherwise the tail lights do not come on at all. This fix might also prevent throwing a code in the ECU as the sensor is still being utilized; I don't know. The dash bulb will still light up on start-up, but go off in the usual manner once the car is running. After that, it stays off as if all the lights were working with ordinary bulbs. This fix however will now require one to occasionally check to see if all their LEDs are working.
  • #11
    The LEDs should outlast your Z31's life. So, the chance that one will burn out is near 0. LED last for approx. 50,000 hours. At 60 MPH, that is 3 million miles. Or put another way, 5.7 continuous years of being on. So the sensor is not really needed anymore.
    Restore it, Don't crush it. They don't make them like this anymore.

    Scott
    85 Turbo, original owner, restored
    93 NA Babied