No announcement yet.

Learning electrical and need a bit of 240 help re:lights

  • Filter
  • Time
  • Show
Clear All
new posts

  • Learning electrical and need a bit of 240 help re:lights

    So now I am tackling some of the electrical in the car. Learning as I go about generic electrical in these cars.

    First time we put the battery to the car and I switched the light control switch to the on position I had power to all 4 side markers, all tail lights [the passenger upper left bulb was not lit, only bulb that was out]. We attempted to turn the engine over which it does turn over well but didn't fire [we found the issue, more work to be done].

    I went back to the rear as I noticed one of the side markers now unlit, to find that everything was now unlit and I hadn't touched a thing inside.

    What I am left with now is the driver side rear side marker stays lit permanently. Even with the key out and the light switch toggled to OFF it remains lit, I need to disconnect the battery to stop it. All interior fuses have been replaced brand new and none are blown. I have working interior indicator lights both via the signal control and 4 way toggle switch but no illumination to any gauge. I have attempted adjusting the rheostat to no avail. Some articles indicate the light switch mechanism on then column can have carbon develop on the contacts. I removed the mechanism and cleaned everything inside. The contacts had a lot of carbon but look like new now along with the thin copper contact tabs that contact them.

    Any guidance on a next step would be great. I'm attempting to understand the electrical schematics/routing but am having a bit of a struggle with making it out. I can follow a wire but I don't understand some of the junctions/destinations/points in between to have the ability to diagnose. As always with my questions sorry for my inexperience.

    I will start checking with a multimeter but I dont have time today to go out, figured I'm inside and would ask. Also, having seen them lit up for a little before this happened gives some hope that power is reaching back there.

    Thanks all,
    Last edited by Caleb; 06-19-2015, 02:03 PM.

  • #2
    Firstly, do you have the harness wiring diagrams and the overall wiring chart? Let me know if not and I can send them to you.
    '72 HLS30-79101 (SOLD)
    '09 370Z Touring 6MT (SOLD)
    '99 Porsche 911


    • #3
      Hi Caleb

      Zak's right. You need the wiring diagram. Google ZenonZcar and you can download the entire service manual for your year. You'll find individual circuit diagrams which you may find easier to follow. I'll print the page and use coloured markers to trace the individual wires, especially if the diagram is black and white. Take your time and you'll start to see it.


      • #4
        I do have the wiring diagram open in the back of the car that you gave me Zak. The nice bound service manual that looks brand new. I understand the wiring in terms of identifying each wire based on the description in the manual and the associated wires/colour combo that should run to each specific piece. I have confirmed I'm at least that far by making sure my tail light bulbs are in their proper location according to the manual. My confusion is coming from trying to follow them back to the firewall and the junctions along the way.

        Great suggestion on the colour coding, my two brother in laws have been into datsuns for a while and did the same thing on two exploded diagrams that they had in the shop. They unfortunately along with the beautiful diagrams are no long around much at all The one helps me with my engine issues and is amazing with wiring complications but lives in Ottawa.

        Im going to run to grab it, find a specific wire and trace as far as I can. That might fix where my confusion is coming from as I will let you know where I get to and we can go from there with the tracing.

        Thanks very much guys,


        • #5
          Ok, with the manual.

          1) Let's track the reverse lights. If I understand it they are red/black. The left side reverse wire ties into the right side reverse wire and goes forward as one wire. I can follow it along the page and ends up in the "Reverse Switch" which makes sense.

          2) "Tail" lights again join together into one wire to go forward [green/white]. The manual runs that wire straight into the [green/blue] coming from the "parking & t/s & side F.". I see that where they junction together the wire then runs downward along the page again as [green/white]. Have those two wires now become one much like how the sister tail light wires became one? This continues down to the Combination Switch.

          3) I see that all of the grounds [black] run together in the back end of the car.

          So here are two different sets of wires wires going to two different locations [Red/Black to Rev. Switch] [Green/White to Comb. Switch]. I notice there is a red wire from the reverse switch that also links up with the combination switch.

          The common is either the ground or the combination switch then? The fact that the rear lights have worked and I saw them all lit moves me a little away from the ground being the issue but instead being the comb. switch. Another point for the ground being ok is that the driver side rear side marker, which always stays lit regardless of the key, is linked to the same ground as the rest of the rear lights so if its on the ground should be ok as it still lights up. Throwing another loop into the mix though, that side marker shares the same [green/white] as the "tail" lights yet the "tail" lights aren't coming on. If they use the same wiring why would I have one of two side markers on and zero of two "tail" lights.

          Sorry for the rambling, this is how I'm reading the manual so I hope some of this makes sense. I've decided not to edit it so that my errors can be spotted in my thinking.
          Last edited by Caleb; 06-19-2015, 04:59 PM.