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Headlight Switch: Contact Reconditioning

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  • Headlight Switch: Contact Reconditioning

    I thought i'd post this up for new owners (or old).

    Intermittent interior lighting and exterior marker lighting failures. Occasional burning smell. Fuses all looked good.

    Corrosion on lightswitch connector #12 causing poor connectivity and high resistance/overheating.

    Plug connector:

    Harness Connector:

    Action Taken:
    Cleaned plug male connector with fine grit sandpaper.
    Harness female connector was beyond repair and further damaged trying to extract it from the plug.
    The female connector was cut off and the wire was cutback and stripped.
    A new female connector was soldered in place.

    These connectors can be replaced with a little effort, instead of using a crappy aftermarket crimp connector.
    (which would get in the way of the harness plug anyway)

    MSpaint rendering of connector replacement:

    I used a metal stick pin with a wooden handle from a dissecting kit. The pin is very thin, strong and not easily bent.
    I've used it for this purpose on many connector repairs under the hood.

    A bit of grease might help keep corrosion from returning, but as i did not have any, i did not use it.

    Intermittent Headlight failure:


    One or Both headlights do not operate properly. Fuses all look good. Been told "Its your switch" over on


    Corrosion buildup on lightswitch contacts causing weak or no connectivity. Contact fingers warped from overheating.

    Action Taken:

    Cleaned contact points with fine grit sandpaper to remove corrosion. Carefully re-adjust contact fingers.

    The original headlight switch from my 84 turbo:

    After a few years, this started giving me intermittent failures. I cleaned and re-adjusted it twice before i
    sought out a replacement at the junkyard. Some owners have good luck with cleaning them, for others its more temporary solution.

    I found this one, i believe its from a latter model Z31 as I've heard the contact fingers on the latter models are of a different metal,
    possibly just a nickle coat?

    (the photos may not show it well, but the contact fingers on the different switches are two very different colors)

    When cleaning the contacts, use a fine grit sandpaper. Try not to remove too much material or you may need to readjust the contact fingers.
    Re-adjusting them is a hit or miss affair and i would try to avoid the trial and error, which is why i got a replacement after two temporary fixes.
    Clean both the upper and lower contact surfaces. Blow out any excess debris.

    Contacts labeled for what they control. (may be reversed but you get the idea)

    • 19mm socket with extension and ratchet.
      Phillips screwdriver.
      Wire stripper/cutter
      Soldering iron
      X=acto blade
      Metal pin
      Fine grit sandpaper.

    84 AE/Shiro #683/Shiro #820/84 Turbo

  • #2
    Nice writeup. Excellent answer to the all too common z31 light switch problems. I also was having trouble with the headlights on my 87 because of the switch. I cleaned it up with some sand paper a while back and its working great.
    "produce second."


    • #3
      Very good writeup. I have been doing this repair for years, and it is uch cheaper than buying a new switch. I do the same type of thing for window switches.
      Chuck Stong
      300+ Parts and Performance owner
      2002 ZCOT president and always active member


      • #4
        Thank you for the write up.

        Terrible idea putting those wheels on...


        • #5
          Ok, I can read how to fix this thing but I dont know where this thing is located. I can see its around the steering wheel from the pics but where exactly is the piece that I need to open up?

          Someone should make this a sticky because I'm sure this happens to a lot of z31's. I'm willing to place money on the fact that this is what is wrong with my head lights now.
          85 Z31 6.0 LSX turbo 766whp/792wtq
          04 GTO, LS6, big cam, porting, N20... underway for summertime daily driver.


          • #6
            Awsome, but does anybody know where the little box is to fix. 84z31 you said you fixed it, where is that box at?
            85 Z31 6.0 LSX turbo 766whp/792wtq
            04 GTO, LS6, big cam, porting, N20... underway for summertime daily driver.


            • #7
              right were the turn signal stick thing enters the steering column. You need to remove the steering wheel and you'll see it on the left.
              Shiro #443


              • #8
                Re: The Dreaded headlight switch

                Another version ..

                '84Z31 GLL turbo|theZenthusiast site: |

                Originally posted by maronee
                PS - by the way your Z31's famous here in japan, dude!!


                • #9
                  Re: The Dreaded headlight switch

                  Beck wrote: I hadn't noticed this before, but seems like a good place to assimilate this info for those wanting to fix the switch and don't know which one they have. The 84 year is easy to know, because it has the cruise controls built into the assembly. As for the others, the white one in the pictures is the late model (actually 1987) and the yellowish one is the older style (a 1985).
                  there are 2 more variants to this switch, the main plug attached to the headlight switch has 3 rows of prongs instead of 2 like the ones pictured.with and without cruise. i wasted 3 hours 1 day by grabbing the switch with the wrong plug at the jy.


                  • #10
                    Re: The Dreaded headlight switch

                    300cars wrote: try soldering a piece of wire from one of the 2 prongs to the other.
                    I dont think thats a good idea, each headlight draws about 4.8 amperes, thats why theres 2 fingers, one for each side. The socket has 1 wire suppliying voltage to each side headlight and theres a 10 Amp Fuse for each headlight, so you are close to the limit connecting them together.

                    i just "Fixed" my problem but without cleaning the contacts (well i did, but i bent the little fingers too much haha), i replaced the "circuit" at the lever using 3 relays a 2 switches (i also dont want to disassemble everything every 2-3 months).

                    im not very proud, but it does the job. Also this circuit lets me have sleepy eyes anytime (when turning the lights on, the eyelids dont raise until you switch from low to high beams, then switch back again to low and then you keep the eyelids open and they close when you turn off the lights)
                    1987 300zx, VG33, Manual, Megasquirt, 450cc, T04,Tial 44mm External WG, ebay IC, crushed dsm blowoff, Apexi AVC-R at 15psi, efan, 3" exhaust with dynomax muffler, LSD.


                    • #11
                      Okay.........I need a little bit of help. I have the steering column removed, my problem is how do I remove the switch so I can clean it. Thanks


                      • #12
                        milo wrote: Okay.........I need a little bit of help. I have the steering column removed, my problem is how do I remove the switch so I can clean it. Thanks
                        Long time no see.

                        You should see 4 small screws on each of the corners. Unplug the switch and slide it out from the column assembly.
                        Originally posted by Andrew84zx
                        tell her your car is so fast it will make her panties fly off
                        545 RWHP & 540 RWTQ


                        • #13
                          nice write up but i got a question for you,my 85 na has low voltage in one of the regular headlights.... would this fix the problem per say? thanks


                          • #14
                            Z-Karma, thank you for the write up! I needed to consult this write up on Friday. I had the issue of the drivers side headlamp only working on high beams and the passenger side headlight only working on low beams. Take apart, clean up contacts, put together VOILA I have headlights that function properly.
                            Shiro Special # 981 Being assembled in my spare time Chromoly acquired!
                            Originally posted by BoostedMamma
                            Heads up makes teh panties drop. BUT I don't have a penis OR a fast car, so I guess my opinion doesn't count.


                            • #15
                              sorry to add another question to this post, But I have just bought a z31 (87) and it has this problem, what the previous owner did was hook up a toggle switch hard wired to the lighting, which works fairly well, but didn't disconnect the power to the stalk so I will com eout to a dead battery from time to time, I'm lazy and just want a quick fix, what wire would I cut to kill the power the the stalk for the headlights and running lights, so that those are just on a toggle switch but can still use the turning signal fucntions