Turn signal turns on headlights

[scotta]

I stumped, but working through problem solving. A nudge or ideas might help

73 Fairlady Z - recent purchase, just getting it road ready. PO has been restoring for 21 years, not run for at least 4 years. 

Headlights work; low beam & high beam + rear lights come on
Hazard switch works with all 4 lights working
If I use the indicators with the hazards on, I can hear the indicator relay also clicking on/off
Brake lights work 

However when I go to use the indicators the headlights come on solid.

Clearly something shorting or incorrectly wired.

[scotta]

Any suggestions or ideas?

[Patcon]

Possible ground issues

[SteveJ]

22 hours ago, scotta said:

I stumped, but working through problem solving. A nudge or ideas might help

73 Fairlady Z - recent purchase, just getting it road ready. PO has been restoring for 21 years, not run for at least 4 years. 

Headlights work; low beam & high beam + rear lights come on
Hazard switch works with all 4 lights working
If I use the indicators with the hazards on, I can hear the indicator relay also clicking on/off
Brake lights work 

However when I go to use the indicators the headlights come on solid.

Clearly something shorting or incorrectly wired.

The turn signals will not work when you are using the hazard lights. The switch for the hazard lights cuts off the power to the turn signals.

What do you mean by "headlights come on solid"?

Also is this a genuine RHD JDM Z?

[scotta]

1 hour ago, SteveJ said:

The turn signals will not work when you are using the hazard lights. The switch for the hazard lights cuts off the power to the turn signals.

What do you mean by "headlights come on solid"?

Also is this a genuine RHD JDM Z?

headlights come on solid = not flashing 

even if I pull the two headlight fuses, the headlights sill come on when the indicator is used. Need to sit down with the FSM more. However the wire colors in the 73 Datsun 240 FSM  do not match. 

Genuine RHD JDM Fairlady Z. 1973 - S30100698. but the electrics look like they are from 1972. 

[SteveJ]

Okay, I'm tracking with you now. There should be differences between the US and JDM wiring, and I do not know if any of the differences are in the turn signal or headlight circuits. @Patconcould be pointing you in the right direction on grounding issues. When you use the turn signals and the headlights come on, are they normal brightness or dim? Can they change between high and low beam?

@kats Do you have a source for the Japanese wiring diagram that you could post?

[kats]

Hi SteveJ , I will look into my books, if I have the one , I will post here .

Kats

Edited May 5, 2018 by kats

[kats]

Hi scotta , I do not know I will be able to answer your questions, but here are some pictures what I have.

Your car looks like late 1972 built, as we can see the last chassis number for 1972 is S30-101613 , your car S30-100698 could be built in September or October .

Unfortunately The service bulletin Sep 1972 ( guide for the changes , this time created new chassis number starting from S30- 100001) does not have a wiring diagram.

But can we use this, a diagram for Oct 1971 ?  Because the headlight switch and the turn signal switch are basically the same up to Sep 1973 as well as the flasher units and the flasher switch.

However, harness connectors had a big change at Sep 1972, they went 10 pins for the dash harness which connects to the body and engine harness.

Sorry for poor quality of the pictures,

hope this helps.

Kats

 

Edited May 5, 2018 by kats

[SteveJ]

Thank you, @kats, for taking the time to post these diagrams. They are of excellent quality.

[scotta]

Kats San, doumo arigato gozaimasu.

Not only will this help with the wiring. It has also confirmed my suspicions that it is a 1972 not a 1973 as believed by previous owner. 

[cgsheen1]

There's a "flash-to-pass" circuit in that diagram.  The Swiss 260Z we had in the shop had that feature and I've heard that the Fairlady's did too.  Check that circuitry and it's associated relay.  The USA models only have the HI/LOW beam selector (switch) associated with the turn signal lever.  Maybe something is mis-wired so the turn signal switch is setting the flash-to-pass relay.

[scotta]

Problem solved. Thanks to the wiring diagram and the 'flash to pass' circuit nudge.(Thx Kats & cgsheen1)

Turns out the previous owner had installed a 1973 US turn signal (he was using that as a parts car), and just plugged it in. 
Turns out the wiring is different between the US 240z and JDM Fairlady Z. 

Attached for reference is JDM version on left, US version on right. Note the turn signal plugs left and right wires are the same but the flash to pass wire is on the JDM one. 

A clean up of the JDM version, rebuild the switches and reinstalled and all working now. 

Other thing to note is the flasher in the JDM version is on the RHS of the car, with all the other electrics.   

Another problem solved, one more step to getting her road worthy. 

 

 

 

Edited May 9, 2018 by scotta
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