Wiring problems - no indicators or brake lights

[Steely]

Hi, new to the 240Z, I’m working through a few issues with my recently acquired 72 LHD US import.
It started with me looking for the green wire to feed the electric fuel pump I intend to fit, I set about removing the radio, which had been really jammed in, and the wiring behind is a bit of a mess, removing the radio I assume I have disturbed something, but I’m not sure what, looking over the wiring diagrams, I can’t make sense of the wiring!
At first I had indicators front and rear (but no hazard) and headlights, but the rear lights and brake lights didn’t work, only the reverse light worked. Also the interior lights didn’t work.
Now after tracing wires and checking connections, the interior lights work, the headlights and rear lights work, but still no brake light and the indicators stopped working! I have a few lose connections behind the console, but none of them connect to each other.
To top it all, I can’t find the green wire for fuel pump, and I found the choke light cable is disconnected, does that connect near the choke lever?
a few pics of the connectors..

Looking at wiring diagrams and looms/connectors, its driving me mad, any help appreciated.

 

[Rob Gaskin]

Hi mate, first of all you are not alone. Many have got confused and frustrated by the wiring and the diagrams.

I'll try to find time to reply fully tomorrow.

Where is your car located?

 

[Steely]

Thanks Rob, appreciate any help, I’m going to blow my own fuse at this rate
I’m located in Worcester.

 

[MaximG]

Most of those plugs are for ancillaries fitted or not fitted. Things like the radio, heated rear screen, AC, illuminated heater control panel, stuff like that. The choke lite has a micro switch on the choke mechanism, and the light is on the Fuse flap. If you see a wire that is red with blue tracer it’s generally for some sort of illumination. I would make sure the large plugs behind the Fuse box are seated properly it doesn’t take much to dislodge them. Also remove clean and check all the fuses.

The fuel pump wire is best traced from the plug that comes from the rear of the car.

 

[MaximG]

Not sure what references you have for wiring diagrams? There are numerous ones even for the 240. Also the US market has a lot more gubbins compared to the U.K. variant.

 

[Steely]

Fuses was my first port of call (I did blow one due to glove box light) also cleaned the fuse holders, took the fuse box out and inspected the rear, then checked all plugs and connections, that got the lights working (interior and exterior) but indicators stopped working, and the brake light hasn’t worked all along, wires are connected at the switch.
In the second photo there is a loose blue female round connector that registers on the volt meter when brake is on/off (but not as I would expect it to) but nothing I can see to connect it to, and lights seem to be mainly green.

Im using the 72 service manual, but the colour codes don’t seem to match, of course it has been messed with a bit over the years, a few splices here and there, but the core loom looks original.

 

[Bazzateer]

there is a loose blue female round connector that registers on the volt meter when brake is on/off (but not as I would expect it to) but nothing I can see to connect it to

Not entirely sure what you're saying re registers when on/off? But if it helps I'm pretty sure the blue female bullet on my 260 is the 12v permanent power to the cigarette lighter?

 

[Steely]

I don’t know but 260Z could be completely different, the 240Z is different depending on early or late, the cig lighter shows blue/white on the diagram, that is another thing that doesn’t work, low on the list.
What I saw on that blue wire is power when the brake is applied and released (but not 12v), unless it is was me losing the plot by that point.

 

[Rob Gaskin]

Hi, first of all did everything work before you removed the radio and started looking for the green fuel pump wire?

I had the same issues as you i.e. messed about wiring and unable to trace anything. I have my dash loom out so I should be able to check things for you however I'm not promising success.

 

[Steely]

Hi, yes, all the important things anyway, I didn’t check the lighter and I think the roof light switch is shot, but lights, indicators, brakes etc. All worked and the bulk of the wiring looks original.

 

[MCBladeRun]

When you said the hazard switch didn't work, that's the first component in the loom for the brakes / indicators on a US 1972. Same as mine. So it could be you've knocked the wiring for it slightly?

My problems have always been indicator stalk related, and since I rewired the brakes to be independent from the indicators, I no longer have issues with the brakes.

 

[Steely]

It’s possible that in checking the wiring and getting the rear lights working. I have disrupted something else, I’m having a couple of days away from it, when I get back I will start again with checking all the connections.

I got a diagram of the indicator and associated wiring from “fiddlingwithZcars” so something else to reference.

rewiring the brakes, how do you do that?

When you said the hazard switch didn't work, that's the first component in the loom for the brakes / indicators on a US 1972. Same as mine. So it could be you've knocked the wiring for it slightly?

My problems have always been indicator stalk related, and since I rewired the brakes to be independent from the indicators, I no longer have issues with the brakes.

 

[MCBladeRun]

It’s possible that in checking the wiring and getting the rear lights working. I have disrupted something else, I’m having a couple of days away from it, when I get back I will start again with checking all the connections.

I got a diagram of the indicator and associated wiring from “fiddlingwithZcars” so something else to reference.

rewiring the brakes, how do you do that?

So, essentially it's running a wire from the brake switch, around to the rear of the car and cutting the brake/indicator wires so that it's separate.

http://www.zhome.com/ZCMnL/240ZTSignalMod/turnsgn1.htm

Have a look at their other guides, I found some of them useful.

I myself have done a special rewiring of the rear clusters so I can keep my US lights, with indicators/reverse lamp on the clear. Don't know if you plan to replace yours with euro spec lenses?

 

[Steely]

Mine came with the euro lenses already in place, the side markets light with the rear lights.
I haven’t spent much time at that end of the car yet, but the wiring all looks original at the clusters.

 

[Rob Gaskin]

Is your 'Stop' fuse ok?

I have altered my wiring and now us a 260 fusebox (more fuses) and separated the stop and hazard wiring. The hazards/Indicators use two fuses 'Flasher' and 'Stop'.

By the way these are green and green/yellow so when looking for the green fuel pump wiring you may have got confused.

I have altered mine quite a lot to simplify it and ease fault finding because of situations like this.

My fuel pump wiring uses the green from the rear but it connects to a fuel pump switch on my dash so I can't trace it through the dash loom for you.

 

[Rob Gaskin]

Also do you have the clear lid for the fusebox which identifies (in a fashion) what the fuses serve?

 

[grb184]

As far as I can tell, the green wire from the fuel pump goes via an in-line 20A fuse direct from the ignition switch (Black/White in, Green Out of fuse ) so if you trace the Black White with from the ignition switch to the fuse box you should see the join taking the power to the fuel pump.

 

[Steely]

Also do you have the clear lid for the fusebox which identifies (in a fashion) what the fuses serve?

I do have the cover, the fuses are all good and the fuse box fittings are clean.
Where is the flasher & hazard relays on these usually? That’s a component I should check. otherwise I think I am resigned to continue tracing and checking connections.

 

[Rob Gaskin]

I do have the cover, the fuses are all good and the fuse box fittings are clean.
Where is the flasher & hazard relays on these usually? That’s a component I should check. otherwise I think I am resigned to continue tracing and checking connections.

The Hazard and Indicator units are the two round ones in the driver footwell on the RHS 'board'.

 

[Steely]

As far as I can tell, the green wire from the fuel pump goes via an in-line 20A fuse direct from the ignition switch (Black/White in, Green Out of fuse ) so if you trace the Black White with from the ignition switch to the fuse box you should see the join taking the power to the fuel View attachment 40105 pump.

It was that 20amp outside of the fuse box that I thought would make it easier to find, I guess I can always run a new wire from the black and white to under the car.