View Full Version : New Harness but no back-up lights :(

12-31-2010, 03:09 PM
First of all, THANK YOU to everyone who replied to my last post with the encouragement to replace my rear wiring harness alone. I live way the heck out in West Texas, where help with such things is sparse, so it takes a lot to muster the courage to take on projects myself. I installed the new rear harness in about three hours, and carefully disassembling my new panels and carpet was the hardest part.

After hooking it all up, the short was gone (FINALLY) and everything works EXCEPT the reverse lights. Now, I see three connections coming out of the harness to go under my driver's seat, but I believe these to be for the buzzer and ignition lock-out devices, all of which are removed from my car. I am wondering where my reverse-light switch is, but even so, it worked with the old harness without these extra connectors being hooked up. Thoughts?

Thanks so much and Happy New Year to everyone!


12-31-2010, 03:29 PM
It's been a while since I wired my car, but you should have a Green/brown wire going to each of the back-up lights; this is the pos side of the +12 volts. Make sure you have a GOOD GROUND at the back-up light sockets.
The other end of that Green/brown wire connects under the dash (I think around the heater box) to the Green/brown wire comming from the back-up switch. The back-up switch by the way is located on the side of the transmission.
Check those grounds! Good luck... you will get it!

12-31-2010, 03:49 PM
Here's the wiring schematics for the TR6 from Advance Auto Wire (https://www.advanceautowire.com/tr2506.pdf) in case you don't have a copy.

12-31-2010, 05:18 PM
I rewired both TR6's with harnesses from British Wiring, back when the original owners had it. In one harness, they made a mistake and left some wires out. Things happen.

12-31-2010, 05:57 PM
Not clear of the exact route of the wiring, but the reverse switch is on the gearbox itself - I think normally there is a short pigtail to tie it into the main harness? Sorry can't help more than that as I have a TR4, no reverse lights at all on that one!

12-31-2010, 06:30 PM
Cole- You could have had my old harness I removed about 10 years ago

12-31-2010, 07:37 PM

I would check the reverse switch on the transmission as suggested and follow that back.

M. Pied Lourd

12-31-2010, 10:36 PM
No relation to the wiring under the seat, as said you should have a harness coming off the transmission. Before you do anything else have you checked the lights by getting power to them?