Cigarette Lighter Problems: Troubleshooting & Fixes

The cigarette lighter in my Octavia isn't working. Troubleshooting revealed that relay number 8 should activate the lighter, but it's not doing so. There's voltage at the positive terminal of the relay (rt/sw), but the other wire (bl/br) should have ground potential, but there's no connection. Which contact activates this relay? Does anyone happen to have a wiring diagram? Thanks in advance.

Hello,

Try disabling the child safety lock for the rear windows.
'On my Octavia, manufactured in September 1999, with SLX trim, it works like this.'

Regards,

Christian.