After searching i still cant find my answer so sorry for another reverse light question!

I have no reverse lights on my s2 escort turbo. I've brought a new switch (located just to the right of the started motor looking from the front?).

Wiring seems good, when i bridge the plug reverse lights come on. New switch so its not that, so could something inside the box be broken causing the switch not to make contact?

Many thaks for any info.