New parking sensors back - still not working.

Hi, a new problem on my RR Westminster 4.2 SC.

I bought two new parking sensors for the back bumper (the two in the middle) that didn't make a clicking noise since my PDC doesn't work at all. all the others made the clocking noise.

Took the bumper of and installed them. Still the same problem.

Can it be something with the cables or do I have to do something more? buy a set of new ones?

Very likely to be one of the splices in the bumper harness, rather than mess about with corroded wiring, I'd recommend a replacement harness.