WTF is happening with my reversing lights?

[PeeBee]

I have not junked with this circuit. I found today that when I de-isolated the earth circuit to the battery the reverse lights illuminated and stayed on with car running, could only extinguish them by again isolating the earth switch on the main battery.

First thing I thought was a faulty reverse switch, maybe sticking or fused shut? I had a look in the manual and it appears to be n an awkward spot, yet the Gregory manual suggests it's a 15-30 minute job to swap it out - on anyone else's car maybe but not mine. First thing I want to access is the plug and loom to disconnect and see if that is the activated circuit or something else. Has anyone here accessed the reverse switch on a TD42 manual box and how did you do it, from nderneath bearing I am hunting the wiring loom plug first or from inside the car via the gear stick access?

Also what else should I be investigating.

[mudnut]

If the switch turns out to be ok, It is most likely a bad earth on another circuit, finding a path back via the lights. Do you have a proper trailer socket fitted or one on a lead that you just run out when needed?

[PeeBee]

If the switch turns out to be ok, It is most likely a bad earth on another circuit, finding a path back via the lights. Do you have a proper trailer socket fitted or one on a lead that you just run out when needed?

I have a standard metal 7 pin plug, new one, thought crossed my mind about the earth on the plug, it's on the list. I am going to isolate the circuit via the fuse if I can't locate the plug, another adventure on my back in the cold!!!

[PeeBee]

OK, so the plot thickens. I took some time off this arvo to dig into this issue. I started at the fuse box under the dash and with the earth re-connected and reverse lights and tail lights on, removed each fuse, went right thru the list, didn't make a difference. Ignition was off though - maybe this was a fault in my process?
Then pulled the plugs off the gearbox loom , one at a time as difficult to see the reverse switch, again, rear lights remained on.
Next down to the drivers side rear loom, decoupled the additional wiring and chased each wire for power, found one after about an hour, which looked like it was being fed from the passenger side of the car.
Moved to other side, clipping off the 200,000 cable ties, and worked my way thru the loom on that side. The original loom is extended to cater for the rear lights as the wagon loom didn't fit the finished dual cab setup. Second last wire within the loom, found the cable with 12.9V on it, its the red one - yep, I know that means nothing but for me at least I have found the cable with the power that has decided to come alive and taunt me. Now the task is to drop the tray side storage drawer, already did this for the drivers side, which will give me easy access to the original loom and the extension wires. So once this is found, I am hoping for a swift resolution and root cause - still a bit weird what has triggered this. Then resolve the problem and re-wire the rear lights again. Getting closer.

I also checked the trailer plug, all connections firm and dry, so does not appear to originate there.

[PeeBee]

Well another day on the ground and chasing wires. Got everything back together, found the constant voltage culprit was a faulty stop pedal switch, which I had already bought to try and resolve the unresolvable cruise control, BUT, no reverse lights still. The circuit is electrically dead , suspect a damaged wire but can't imagine the coincidence of the failure of the brake circuit and reverse lights. I jumper end a temp supply to the lights and they work fine, so traced out the wiring diagram tonight and found the fuse feed so will look at that specifically in the morning, bloody bee stings.

[mudnut]

Check that a rodent has chewed some of your loom.

[PeeBee]

Ok I did a Google search for the fuse and it was wrong, the feed to the reverse lights is off the 10amp fuse feeding the dash lights, so logical. Anyway the issue turned out to be a broken leg of the fuse, not blown, so replaced the fuse, jury wired it up and bingo, reverse lights. Live circuit resolved by replacing the faulty brake peddle switch, so another full day but glad it's sorted.

[PeeBee]

Hey, I have been struggling with looking for new posts, always clicking the 'new post button' but tried the 'whats new' tab on the scroll bar and the latests posts come up wish I knew about this distinction before - refreshes every time instantly.