Early Hazard Switch

Well, after repairing my friend’s turn signal switch a month ago, he re-installed the switch, but his turn signals still didn’t work. I used a meter to check for voltage coming into the switch and found none. I checked the voltage coming into the turn signal flasher and found it had voltage. That turned my attention to the hazard switch because the hazard switch has contacts to complete the circuit for the turn signal voltage coming off of the flasher. He had a spare hazard switch at home, so later he swapped it in and found that he had working turn signals.

He decided to give me the old switch to see if I could get it working again. The first thing I noticed was that the wire colors on the switch did NOT match the wiring harness. Since this is the only early hazard switch I’ve touched, I don’t know if that is typical or not.
Early 240Z Hazard Switch
I checked the connectors against figure VI-2 (page 33) of the 1971 S30 Supplemental Chassis Manual. However, when I compared how the connector was wired to the switch, it didn’t make sense to me. (Today, I realized the problem. The drawing shows the connector as it pinned in the dash harness. I needed to use a mirror image of the 6 pin connector to get it aligned with the switch.)
Here is a picture of the back of the hazard switch.
Back of Hazard Switch
Here are the connections with the dash harness colors as viewed from the back of the hazard switch
Hazard Switch Contacts with Wire Colors
When the switch is off, it completes the circuits to the G (green wire) contacts for the turn signals and to the GY (green/yellow wire) contacts for the brake lights.
Hazard Switch Contacts with Switch OFF
When the switch is on, it closes the contacts that let the green/white wire complete the circuit going out to the front and back turn signal lights.
Hazard Switch Contacts with Switch ON
G – Green
W – White
R – Red
Y – Yellow
B – Black

Getting to the contacts requires bending the tabs back slightly on the switch body. These tabs are fragile, so be careful. After bending them back, you will need to pull on the wires and rock the circuit board back and forth to get it to come loose. After you see a little gap between the board and the switch body, you can use a screwdriver to pry the board out carefully. If you just pull on the board, the rockers can come flying out. That’s what happened to me. Fortunately, I found the rocker.
Here is what the rocker looks like.
This side makes contact with the contacts on the board.
Hazard Switch Rocker - Contact Side
This side makes contact with the switch lever.
Hazard Switch Rocker - Switch Side
You can see some of the corrosion from the years of service. If you look at the rockers carefully, you can see how the top part is insulated from the middle and bottom.
Here is the inside of the board.
Inside Circuit Board
You can also remove the switch lever to clean it. Be careful not to lose the spring. It provides the tension to push against the rockers.
Hazard Switch - Switch Inside Parts

I cleaned up the board and rockers with brake cleaner, since it’s a good degreaser. Then I sanded the contact points with 1000 grit sandpaper.
Hazard Switch Rocker After 1000 Grit Sandpaper
Hazard Switch Circuit Board After 1000 Grit Sandpaper
I bent the fingers on the rocker slightly to put them closer to the contacts.
Hazard Switch - Rocker and Circuit Board in Profile
You can see the top part of the rocker in contact with the pads on the board.
I placed a little dielectric grease on the back of each rocker where it comes into contact with the switch body. This is how it came from the factory.

The next step is putting the board back in the switch body. I prefer to lower the switch body onto the board so the rockers stay in place. I suggest checking continuity of the contacts at this time. Carefully bend the tabs. I broke one off, but then I compressed the sides to hold the board in place. I’m going to see if I can devise some sort of fix for broke tabs in the future.

This entry was posted in 240Z, Electrical, Tech Tips. Bookmark the permalink.

7 Responses to Early Hazard Switch

  1. Pingback: Two black & one green wire/ solenoid on 72 240Z Auto.

  2. Pingback: Hazard switch - 78 - Nissan : Datsun ZCar forum :Nissan Z Forum: 240Z to 370Z

  3. Pingback: Early Hazard Switch

  4. Pingback: Turn Signals and hazards do not come on

  5. Pingback: Hazard lights work, but turn signal lights don't.. Any ideas?

  6. mIKE says:


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