Reversing light issues!!

Morning ladies and gents,
I have a diesel freelander TD4 Kalahari(2003). For the most part it’s been a fairly decent runner. However, I’ve had a recent issue with the reversing lights blowing the 15A fuse when I put the car in reverse. The brake lights are functioning ok. I’ve removed the reversing lights switch from behind the passenger side front wheel and when reconnected to the wiring the reversing lights function as they should without blowing the fuse. This indicates that the wiring is sound. The fuse only blows when the switch is screwed back into position, the wiring reconnected and the car put into reverse. Any help with this would be much appreciated!! Mike.

Maybe there's an internal fault with the reverse light switch, which is shorting through the gearbox casing?

Hello Nodge,
I replaced the switch with a new one but still having the same issue.

Have you checked the light unit itself could be corroded causing earth wire arcing.

saxavordian said:

Have you checked the light unit itself could be corroded causing earth wire arcing.

Click to expand...

The switch functions correctly and the lights operate without blowing the fuse when the switch is removed from the gearbox. It’s only when it is screwed back into the gearbox and operated that it blows the fuse.

Without fitting the switch and the wires connected does the switch have a plunger to press in. If so you can discount the gearbox and concentrate on the harness with a multimeter.

saxavordian said:

Without fitting the switch and the wires connected does the switch have a plunger to press in. If so you can discount the gearbox and concentrate on the harness with a multimeter.

Click to expand...

with the switch removed from the gearbox and reconnected to the wiring the lights work without blowing the fuse. It’s only when the switch is screwed back into the gear box and the wiring reconnected that it blows the fuse. To me this indicates an issue with the gearbox?

MikeJB said:

with the switch removed from the gearbox and reconnected to the wiring the lights work without blowing the fuse. It’s only when the switch is screwed back into the gear box and the wiring reconnected that it blows the fuse. To me this indicates an issue with the gearbox?

Click to expand...

Sounds like an earthing issue. Are you able to earth the gearbox to the chassis with a spare jump lead to test.

saxavordian said:

Sounds like an earthing issue. Are you able to earth the gearbox to the chassis with a spare jump lead to test.

Click to expand...

Same issue even with a temp earth from gearbox to chassis.

2 wires to the switch, so I would assume no connection to earth, just a switched pair.
If so, with the switch out of the gear box do you get power from the switch body and known earth when depressed.
If you did that would short to the earth of the box and blow fuses.

J_D said:

2 wires to the switch, so I would assume no connection to earth, just a switched pair.
If so, with the switch out of the gear box do you get power from the switch body and known earth when depressed.
If you did that would short to the earth of the box and blow fuses.

Click to expand...

Yeah the switch is knackered. 12 volts from the switch body to earth. Was overthinking everything as usual it’ll teach me not to buy from eBay!!

MikeJB said:

Yeah the switch is knackered.

Click to expand...

Wasn't that mentioned earlier?

Nodge68 said:

Wasn't that mentioned earlier?

Click to expand...

You called it! Didn’t think it could possibly be a fault on a brand new switch bought for pennies off eBay haha!