Reverse light wiring????

Evening, impending MOT and no reverse light! I bought a new light unit as had thought the terminals had rotted (1990, 90) but it appears that would be too easy. I’ve metered the switch on the gearbox and it has 12v+ going through it OK, so was planning to run a new wire rather than hunt the break. This is where my knowledge runs out....is there a quick way to check he integrity of the live and earth separately at the lamp? To save me running both, if not, how best to wire it??? Thanks in advance.

You dont need one for the MOT, its not testable.

Do you not have a live at the lamp?

Reversing lamps testable on vehicles first used from 1/9/2009. So yours is not testable.

Wimblowdriver said:

Reversing lamps testable on vehicles first used from 1/9/2009. So yours is not testable.

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Really? When did this happen?

nobber said:

You dont need one for the MOT, its not testable.

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Brilliant, one less thing for it to fail on!
Thanks

Latest MOT rools, think it came in May 2018. My reverse light had needed fixing for a couple of years but had to get it sorted for the new MOT last September. Was an easy job to change the switch on the cog box.

nobber said:

Do you not have a live at the lamp?

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I’ve got a live on the out pile of the reverse switch, but dead at the lamp. If I was to run another wire...what goes where? Take the live straight from the switch and then an earth to the lamp.
Ideot level instructions would be greatly appreciated!! Thanks

sounds good to me. take it from the output of the switch.

I'd start with just running a new live from the switch to the lamp. Having proven you have no live feed at the lamp, there;s no reason to suspect the earth needs replacing too at this stage. Good luck. (Isolate the old live wire, in case the root cause is a short to earth. That is, cut it and replace with your new wire, don't use a 'piggy back type' connector).

When you tested the lamp you did earth your meter to something other then the lamp body? Sorry, have to ask.

Oh, forgot to add, you did check the connections where the lamp connects to the main chassis harness? Bullet connections behind the lamp body?
Unless something damaged the harness which would be pretty obvious as most of it runs inside the chassis and as a result is fairly well protected these rear chassis harnesses are pretty bullet proof.