No brake lights

Hi guys
A little help needed. I've lost all three brake lights. Checked bulbs and all ok. Checked fuses and ok. Pulled housings out and wiring appears intact. Replaced the brake light switch and stilll nothing.
One of the tow bar connectors ( the white one) looks corroded but the screws are shredded. Could this be the problem before I pull it apart?
All help appreciated
(its a 2002 td4)

Is there power getting to fuse? Is there power at brake light switch? New switches have been known to be faulty!

I'll test power next cheers freelance - just slowly working from least expensive option upwards. If there's power I'll try another switch. Then god knows what.

Well, checked power to fuse and switch and no problems. Just fitted switch number 3 and still no lights. Could it be the wiring on tow bar?

You could do a simple test with brake light bulb and two wires and probe the tow socket if you do not have a multimeter. The brake light switch is connected to the brake pedal so could have failed on the toggle button.

I'll try and test tow bar socket. This is second new switch saxavordian so I'm pretty sure its not the switch. I'm running out of ideas and electrics aret my strong point.

If you can download the wiring diagram for the model this might help trace the issue.