206 no reverse lights

[chriz1]

I have no reverse lights on my 206 hdi, fuse is ok, bulbs are both good, I've taken off the the multiplying to the gearbox switch and tested with a multi meter I get power on the green wire fine, not sure what the other is meant to do whether it carries the signal back but it doesn't buzz with the multimeter when I touch against an earth point so I don't think it's earth??
I also took out the switch and tried the multimeter on buzz setting on the terminals and pressed the switch nothing buzzed.

The other thing I tried is to bridge the multi plug terminals with a bit of wire and this didn't activate the reverse lights.

Little confused now, can anyone help

[chriz1]

Mine was a connector that simply hadn't been plugged back in, near the firewall in engine bay. Think the previous owner had the cambelt done before selling and garage couldn't have plugged back in