Rear Hazard Lights

Dedicated to the memory and knowledge shared by Jim Mettler - All things relating to the flow of electrons in a Pinz.
Post Reply
User avatar
Mead
Canada
Posts: 52
Joined: Sat Dec 10, 2011 10:12 am
Location: Barrie, ON, Canada

Rear Hazard Lights

Post by Mead »

Hey Guys,
I've lost power to my rear hazards. I still have brake lights, markers and signals but no rear hazards although the fronts still flash.
I've done a bit of digging on here and read that it might just be the hazard switch itself. I just replaced the flasher relay last summer and all was working then and now suddenly the rears don't flash but the fronts still do. Anybody able to confirm this or had the same problem?

Thanks for any help in advance.
Josh
Barrie, Ontario, Canada
'82 - 712AMB/M
User avatar
BobbyD
United States of America
Posts: 120
Joined: Thu Oct 01, 2009 12:06 am
Location: Carlsbad, CA

Re: Rear Hazard Lights

Post by BobbyD »

Same here. Front side lights flash great but back lights do not. Kinda defeats the purpose... They used to flash. Consulted with experts (Jim and Scott) and was told to replace the actual switch. I am awaiting delivery. EI has them in stock.
1971 710K S
N2PNZ
User avatar
Jimm391730
United States of America
Posts: 1456
Joined: Wed Apr 14, 2004 10:58 pm
Location: Idyllwild, CA

Re: Rear Hazard Lights

Post by Jimm391730 »

Jim M.
712W and 710M
User avatar
Ian
Australia
Posts: 50
Joined: Tue Jan 01, 2013 5:46 am
Location: Tasmania

Re: Rear Hazard Lights

Post by Ian »

I've just replaced my flasher unit with a Bosch one and had the exact same fault. No rear hazards. When I took the two bolts off that held the old flasher unit on, I didn't immediately notice that a wire with a ring terminal on the end is clamped in place and earthed by one of the bolts. Everything worked except the rear hazards. I spotted the wire hanging loose and earthed it and all good again. Maybe you have the same problem? The wire was on the forward side of that plate so not easy to see..
User avatar
Mead
Canada
Posts: 52
Joined: Sat Dec 10, 2011 10:12 am
Location: Barrie, ON, Canada

Re: Rear Hazard Lights

Post by Mead »

Rear hazards are fixed! :D

Thanks everyone for your comments and suggestions. Here's what I found and how I fixed them.

Like Jim I wanted to see inside that hazard switch to see how it worked and why it might have stopped rather than just replace it and ask questions afterwards. After studying the wiring diagrams for a few days I was scratching my head wondering why I couldn't just jumper out the switch and get the rear lights to flash. So with the switch cover off and the power on I carefully started to trace the circuit through the switch when I realised that the small relay in the switch itself was not energizing nor was the lamp in the illuminated handle flashing. It was then that I realised that the face of the switch is also a ground in the circuit completing the relay circuit allowing the rear lights to flash.

Notice the corrosion on the face of the switch
Haz-Sw.jpg
Haz-Sw.jpg (26.68 KiB) Viewed 2938 times
Small relay in switch
Haz-Sw_2.jpg
Haz-Sw_2.jpg (25.85 KiB) Viewed 2938 times
Cleaned up ready for re-install
Haz-Sw_4.jpg
Haz-Sw_4.jpg (25.65 KiB) Viewed 2938 times
Next I cleaned up the face of the switch quickly on the wire wheel and re-installed and voila flashers that work front and rear.
Hope this helps someone else in the future.
Josh
Barrie, Ontario, Canada
'82 - 712AMB/M
Post Reply