Fed up, rear lights and instrument lights.

Fed up now, ive cleaned the earth near the fusebox and all the spade connectors and with a multimeter checked its earthed well. In the boot the earth is fine, checked once again too with multimeter. Im having to run around with my fog lights on and cant see the speedo at night, when it was working could hardly anyway but thats besides the point.
On the light switch itself there is a grey connector thats loose (two grey wires, one grey leading into a connector block thats joined by a black and white), and two points that it can go into the light switch. pushed into either it doesnt do anything, ill get some photos to show you!
Nick

OK so seemingly the lights came on last night, ive found if i leave the light switch on before i start the car they will be there (still intermitantly), but as soon as i got home and turned the lights off and on to check, they stopped working when i flicked back to on. Ive had a look at the wiring diagram for an early 1.6 gti and cant quite make sense of it, from what i know the clock light and rear lights must be in series as when i have no clock light the rear lights wont be on!?!