Write up: How to swap out a 240z turn signal switch.

[qlynxer]

If your 240z owner, you probally have a good collection of turn signal parts.  Here's mine

 

This write up is to show how to swap out a 240z turn signal switch.  I swapped in a switch from a 260z since i had a nice one lying around.  A switch from a 260 or 280 should work fine since they are pretty much bolt on except for the wiring and plugs.  You could just use like a three way toggle switch if you wanted to.  

 

 

The most complicated part is that the 240z switch has to control braking functions as well as turn signaling.  

Heres a picture of the back of turn signal itself.  The white switch on the left with the big RY, B, and RW wires controls the head lights and high beams. Now look at the brown board with six wires going into them.  This is where brake lights and turn signal functions all collide in a jumbo heap of wires.  

This area is a cause for a lot of problems with turn signals.  I've opened up and cleaned my original 240z switch plenty of time and it usually helps but the problems always eventually come back.  

 

Now here's a picture of a 260z version.  Its much simplified.  The headlight/ highbeam wiring and plug is identical.  But when you look at the signaling switch, its a basic three wire setup.  

 

In order to swap the switch, you must first separate the the braking function from the signaling function.  THis greatly simplifies the wiring.  You are going to be doing the euro/JDM tail light mod.  

 

Instead of your brakes lights looking like this.

 

THey will now look like this.  Your brake lights will now be strictly the top row of lights and your turn signals will be the two lower outer tail lights.

 

Look under your dash right where the brake pedal is.  There will be a little switch mounted there.  This switch has two wires.  The one on top is constant power going in.  WHen you step on the brake this switch activates power to the lower wire.  You must cut the lower wire and this wire is now your "new brake light wire".  

 

Now go to the back of the car.  If you look at the tail light harness, the upper outer light bulbs are dual filament.  There are three wires going into it  The Black wire is ground,  GW wire powers on the running lights, while the green wire used to power the brake lights untill you cut it a minute ago up front.  

You now want to cut the green wire on both upper outer bulbs, and then splice that into the "new brake wire light".  Now  your brake pedal sholuld power these two bulbs directly,  Your turn signal switch is now separated and doesnt have to deal with any braking functions.

I chose to also incorporate the upper inner bulb as a running/braking light as well.  Normaly there will be a single filament bulb there which in my car only turned on when i had the running lights on, I wired in a dual filament bulb and wired it exactly like the upper outer bulb.

 

 Now you can figure neat trick ways to set up your brake light options here.

http://www.xenons30.com/JDMtailwiring.html

 

You must complete this tail light modification before you can swap the turn signal switch itself.

 

Now you can bolt on the newer turn signal switch.  On both 240 and 260 there will be a 3 wire plug that powers the headlight/highbeam/horn.  THis plug is identical on both switches and should plug right in.

 

There will be a second plug that'll be different.  In the 240 its a 6 pin plug but only 5 are used.  In the 260 there will be a three pin plug.

 

 

Here's how your going to wire them.

 

Refer back to the first picture of the 240z switch.

The top GB and WR wires are for the front and rear right turn signals.  You can splice them together for now.  This is your "Right side wire" 

The bottom two GR and WB wires are for the front and rear left turn signals.  Wire these together.  This is the "Left side wire"

Ignore the GY, this was the brake light wire untill you re routed it. 

 

Now on the 260z switch, the three wire plug has the following colors.  WB, WR, and green.

WR goes to "right side wire"

WB goes to "left side wire'

 

On your stock 240 turn signal there will also be a single green wire with a female spade connection. In the pic below its the wire at the bottom.  

 

 In my car this green wire is connected to a white wire coming from the harness.  This white wire is powered when the key is in the on position.  You want to connect this wire two the green wire coming from the 260z three wire harness.

 

Now you can dice and splice your harness anyway you like, but i choose to use a few extra connectors i had lying around and built this simple wiring harness so i can change back to my original 240z turn signal if i wanted to.

 

 

 

That should do it.  

 

Here are a few extra notes.  

If you happen to have a 280z turn signal switch, it has a single 6 wire connector that is different from the 240z one. The 280z 6 pin plug is exactly like a 260z plug ,they just combined the 3 wires from the headlight/highbeam/horn plug into the 3 wire turn signal switch into one 6 pin switch.  It should be pretty much the same swap.

 

If you want to get extra fancy, you probally should wire the "new brake light wire" into a simple relay.  I chose not to since my bulbs are led.  If i were still running regular bulbs i would have definitly added a relay.

 

Hope this helps out.

Good luck 

Quan L

 

 

 

 

 

 

 

 

[raven12]

Great info. Thanks!