Hazard Switch/Turn Signal System

[Teekass]

After spending much time searching threads and tracing wires, I thought I would post my findings on how the Hazard Switch and Turn Signal system works on my '77 2+2. After learning how it works, it's really not that complicated. The Hazard Switch is basically a double poled "On/On" switch. When the Hazards are turned OFF, the turn signals are turned ON (and vice/versa). When the Hazards are turned OFF, current still flows into the switch (from a switched hot power source), through the switch and supplies the Turn Signal system. When the Hazards are turned ON, it kills the current to the turn signals and a different power supply (constant hot) flows through the switch and supplies current to the Hazard system. This is why a bad Hazard switch can dork up the Turn Signals.

 

 

 

 

Double-click or print to get a better view.

 

The hazard system current comes from the fuse box constant hot red/white wire, goes to one of the poles on the hazard flasher, out of the hazard flasher via green/blue wire to the hazard switch harness clip where it turns to green/white, then to the hazard switch, then out of the hazard switch as green/black (right side flashers) and green/red (left side flashers)....These wires stay the same color when passing through the harness clip.

 

The turn signal system starts with switch hot current (solid green wire), goes to the hazard switch harness clip, stays solid green when it passes through the clip, then goes to the other pole on the hazard switch. Current comes out of the hazard switch on the other solid green wire, goes to the harness clip and turns to green/ yellow, then goes to the turn signal flasher. It then goes out of the flasher via a solid white wire to the harness clip at the turn signal lever on the steering column. This wire turns solid green when it goes through the harness clip and is soldered onto the center of three wires on the back of the turn signal lever. When the lever is moved up or down, it sends current to either the top or bottom of these three wires white/black is left side turn signals (which turns to green/red when passing back through the harness clip), and white/red is right side turn signals (which turns to green/black when passing through the harness clip).

 

 

 

 

 

The third circuit that goes TO the hazard switch (but doesn't actually go THROUGH the switch) is the little "Hazard" light (right below the switch) that illuminates when you turn on the headlights. Current goes to the light via the green/white wire that turns to red/ blue when passing through the hazard switch harness clip. Current goes through the bulb, and out through the black wire which turns to red/blue when passing back through the harness clip.

 

I'm not sure what year car this schematic came from, but the wire colors were exactly the same on my '77, except that it doesn't mention the changing colors when passing through the harnesses....I'm pretty sure my harnesses are all factory though.

 

I wish I would have taken pictures of my Hazard switch when I took it apart to clean. It was extremely simple though, and it works great now......There are 4 screws on the bottom of the switch. Remove them and pull off the cover. Be careful not to lose the spring that sits in the hole on the bottom side of the switch, or the piece of plastic on the end of the spring. From here, you can see the electrical contacts. The lever simply lifts off and is easily cleaned with a wire brush or similar.

 

Hope this prevents some headaches someday!

[Daeron]

I have been browsing and reading for some time now, and have yet to stumble across this information. I motion for sticky status, this was an excellent post. Many thanks; this has stumped both my father and I on two different vehicles. He got his figured out, (although I do not know if it is "right") but my signals have never REALLY worked.. (once in a GREAT while, dimly, and slowly..)

[COZY Z COLE]

I motion for sticky status, this was an excellent post.

 

 

I agree...

 

 

 

LARRY

[Teekass]

Wow, my first sticky....thanks alot guys !

 

Hey Daeron, my signals were weak and intermittent also. After cleaning the hazard switch and the turn signal switch, my signals work great. I mentioned how I cleaned the hazard switch, but not the turn signal....and I'm pretty sure these are the only 2 moveable contacts in the system. If you look at the last picture in my original post you can see 2 phillips head screws (one above and one below the 3 wires). Remove those 2 screws and the brownish colored plate will come off. Inside there is a U-shaped contact that fits up inside the turn lever. Mine was so gunked-up that it didn't even fall out, but be looking for it. I pulled the U-shaped contact out and cleaned it, along with the contacts on the inside part of the brown plate. It's sort of hard to explain but makes perfect sense once you take the brown plate off. Basically one leg of the U-shaped contact sits between the green wire and the white/red wire, and the other leg sits between the green wire and white/black wire. When you move the turn lever up it connects the green wire and white/red wire (down connects the green wire and the white/black wire). It was not hard at all though.......the hardest part was the time it takes to get to the turn signal assembly, and get it removed.

[Daeron]

Wow, my first sticky....thanks alot guys !

 

Hey Daeron, my signals were weak and intermittent also. After cleaning the hazard switch and the turn signal switch, my signals work great. I mentioned how I cleaned the hazard switch, but not the turn signal....and I'm pretty sure these are the only 2 moveable contacts in the system. If you look at the last picture in my original post you can see 2 phillips head screws (one above and one below the 3 wires). Remove those 2 screws and the brownish colored plate will come off. Inside there is a U-shaped contact that fits up inside the turn lever. Mine was so gunked-up that it didn't even fall out, but be looking for it. I pulled the U-shaped contact out and cleaned it, along with the contacts on the inside part of the brown plate. It's sort of hard to explain but makes perfect sense once you take the brown plate off. Basically one leg of the U-shaped contact sits between the green wire and the white/red wire, and the other leg sits between the green wire and white/black wire. When you move the turn lever up it connects the green wire and white/red wire (down connects the green wire and the white/black wire). It was not hard at all though.......the hardest part was the time it takes to get to the turn signal assembly, and get it removed.

 

I was never very enthusiastic about trying ti fix the turn signals.. most of my "trying" consisted of blindly spraying PB/WD-40/electrical cleaner into the mechanism of the switch, and rummaging around in my uncles parts looking at other turn signal switches and theorizing plugging them into my car to see if it would work.

 

BUT, I have examined enough switches, and enough mechanisms, that I really only even skimmed what you said. As soon as I went and looked at the part you mentioned in the photograph, I understood exactly what would be found under there and knew you were right on... Somehow looking at that bit before didnt quite click in my head.. I was stuck on the concept that maybe the large copper spring pieces that touch the base.. kind of making a C shape around the steering column.. I had thought that THOSE were the contact points for some reason (this was some time ago, when I was still occassionally looking at this problem.. I have learned a great deal and had alot more electrical experience since this time period )

 

Anyhow, thanks for the enlightenment!

[Teekass]

I was stuck on the concept that maybe the large copper spring pieces that touch the base.. kind of making a C shape around the steering column.

 

OMG, whoever designed those things was either a genius or completely strung out on shrooms or some other hallucinogen. I had a problem with my turn signal lever not staying engaged when turning to the right (http://forums.hybridz.org/showthread.php?t=123390). I was able to fix it, but didn't even come close to understanding exactly how that thing works mechanically.....geez!

 

I'm glad my post did some good, and thanks for the motion to make it a sticky .

 

Oh yeah, if you remove your turn signal assembly, it would be a good time to clean and WD40 the springs under the arrows, and make sure the ears that are hashed in red move freely and return to their original spot. These ears are what returns the turn signal lever back to off when you turn the steering wheel back to center.

 

[Daeron]

Turn signal lever won't stay engaged

 

There, now theres a link to that thread in the sticky.

 

Productive couple of photos, there! thanks!

[chrism]

Dude,

This is great. I am doing a swap and was checking all my lights.

I noticed that the turn signals were not working and was thinking that it was going to be a real pain trying to trace the wires.

I do have my center console out and the hazard is disconnected. This is going to same me a lot of time. Thanks

[deja]

Very cool. Timing is everything, I just happen to have pulled my turn signal switch out today and will clean it up. Thanks for the hints.

[terrycoxusa]

There's some great advice here. I didn't have 4 way flashers working, I started checking the wiring and the connector from the console wiring to the firewall loom had some bad wires, it looked like the heater core may have been leaking on it, it was all corroded. I fixed this, gave it a good coating of dielectric grease, and now everything works fine.

[RB26powered74zcar]

My car has been completely re wired using a EZwire 12 circuit harness, and everything works like it should on the steering columns combo switches, except when I apply my brakes, my front amber running lights come on.

 

Until I push on the brake pedal, the front turn signals and running lights work correctly. Having the brakes on will not affect the front turn signal lights at all, just the running lights up front.

 

So... with out any lights turned on, I push pedal and front amber running lights activate.

With lights turned on, pedal has no effect on front amber lights..... Any idea what this could be??

[Daeron]

My car has been completely re wired using a EZwire 12 circuit harness, and everything works like it should on the steering columns combo switches, except when I apply my breaks, my front amber running lights come on.

 

Until I push on the break pedal, the front turn signals and running lights work correctly. Having the breaks on will not affect the front turn signal lights at all, just the running lights up front.

 

So... with out any lights turned on, I push pedal and front amber running lights activate.

With lights turned on, pedal has no effect on front amber lights..... Any idea what this could be??

 

sounds like a confusion in the way the "brake light" circuit and the "running light" circuit are connected as far as wiring for switched power.. I don't know any of the details of how the car is wired, but it should be a simple pair of wires that was installed backwards.

[cheney119]

I had a bad right front signal so I've been reading all the posts on the turn signals. I replaced my signal switch, cleaned my emergency flasher contacts, I replaced the right signal (with one purchased from e-bay) I even went over to Napa and purchased 6 tiny files to clean the contacts and dielectric lubed them. But it all came to nothing.

 

I was at a loss of what to try next and lo and behold the front right signal started working today out of bloody nowhere. It works perfectly signal light and flash. I suppose it just comes down to connections, but why today as opposed to three weeks ago. My advice to anyone else is to stick with the basics. Those connections are difficult to clean properly, it took 30 years to get them that dirty.

 

Doug

[VinhZXT]

I did 2 write ups to described how the turn signals work on both the Z and the ZX and they are in the FAQ. I mentioned the culprit are mostly the black connectors on the passenger side transmission tunnel. The power goes thru those connectors and over time caused corrosions. That is the first place you should check and clean. GL

V.

[RUSSJZ-ZED]

Brilliant information, Mr Teekass, spent hours trying to find cause of one side of car not working on RH turn( but all ok on hazzard) after finding this took me 1 hour to locate problem and repair.(that little "H" shaped spring loaded thingee under the brown plate had shorted out and deep fried it)

Workshop manuals shoud be written like this!

Would have rated this post 10 stars if it were possible.

[Guest JimmyCrackCorn]

Will this work for a 1973?

[TXCASE801]

hey everybody, car is going slowly but have now ignition (engine finally spins over YAAAAAAAAAAA) hazards, headlights and parklights going. i have some questions?

 

1. does the dash need to be installed to make the turn signals work?

 

 

2. only 1 side of the fuze box is hot, (red wire side of box). ???? help

 

3. i have a 6 spade male wire connector under the dash on the drivers side that looks kinda like the same connector as the ignition switch, what does this connect to.???

 

4. i have a dash out of a late 74 Z, (parts car) is the dash wiring completely different than a 77 Z?

 

i have the electron microscope assisted wiring diagram, chilton and some found on this site, please help. im soooo stuck. thanks JJ

[Oddjob]

As it happens, I've been trying to repair a broken hazard switch. I have learned so far that 1- Nissan doesn't make the switch anymore, 2- there isn't any NOS to be found, 3- used switches are nearly 40 years old and thoroughly picked over, and 4- the original wiring doesn't make any logical sense. I had intended to simply substitute an industrial DPDT and be done with it. At least on a '71, that isn't possible, due to the pervese switching logic of the original. Attached is a reproduction of said logic, copied from an original service manual. Perhaps it will be of some help to you. (Original uploaded file corrected 9/25/10)

71-’72 240Z Hazard Switch Logic.pdf

Edited September 25, 2010 by Oddjob

[Oddjob]

As mentioned above, my original hazard switch is completely gone, and it has become unlikely that I will find an acceptable original part. The first step toward creating a hybrid replacement is to understand what the original does. So, I spent a couple of hours with a magnifying glass and drew the attached circuit diagram to show the logic of the connections. This drawing does make a bit more sense. However, please note that it leaves out the brake light and the turn signal circuits for the sake of clarity. Both of these circuits are downstream of the hazard circuit, which is why a bad hazard switch takes out your turn signals and brake lights as well.

Emergency Flasher Circuit.pdf

[Oddjob]

As mentioned, there are no emergency flasher switches to be had for this repair. Attached below in the PDF is the "fix" I ultimately used. This is a hybrid circuit to replace the OEM part. It has the advantage of consisting of readily available industrial components which are actually much higher quality than the original. The relay is rated for 10,000,000 operations, which should be good for something like 4,000 years of regular use. The switch is water and oil-proof, and rated for 15 amps at 12VDC (each pole). The major parts are as follows:

 

8002K34 oil-spray-tight washdown toggle switch, DPDT, on-on, 15A., quick disconnect terminals @ $27.33

69585K55 compact relay, 12VDC coil, 4PDT, 15A., @ $13.11

70205K26 switch seal and boot @ $3.54

 

These parts are from McMaster-Carr.

 

The first photo is the stock switch (sorry about the bad photo). The wiring will be cut off the back of the switch, and new quick-connect terminals will be soldered and heat-shrunk onto the wiring. This allows you to connect the hybrid circuit directly to the stock wire loom with no modifications. You can then also remove it for service.

 

The second photo shows the components before installation. There is no picture of the completed installation, as you can't get a camera up behind the dash to take a shot. The completed installation does work in the car, and has improved the brightness of the lamps, suggesting there was some resistance through the stock part.

HAZARD SWITCH WORKAROUND 2.pdf

Edited November 5, 2010 by Oddjob