1987 W124 300CE Tail Lights Not Working

[pookybbb]

Hi All,
I'm wondering if anyone can give me some leads on this issue. 1987 W124 300CE. All the tail lights and number plate lights are non functional. Checked the fuses #3 and #8 and they are fine. Checked the globes, they are fine. There doesn't seem to be any power getting the circuit. I had been messing with removing an after market alarm, but I don't think that has caused the issue. The factory alarm is still fitted, but again, not sure that should affect tail lights? It's got me scratching my head! Any suggestions would be much appreciated. Thx

 

[pookybbb]

I did a little more troubleshooting. It now appears the tail/parking lamps are the ones not working (rear indicators, brake and reverse lights are working). The instrument cluster/interior light do not come on. Also when the standing lamps are switched on, neither front/back/left/right work. Interestingly the headlamp flasher/ high bean also does not work. Not sure if that could be related? Any ideas would be much appreciated. Cheers