[tricky]

imported post

Assuming the bulbs are OK Is the licence lamp working? check voltage on the brown wire coming from the brake/tail light sensor, There are two brown wires. If there is voltage on both then problems in the wiring from there, check grounds, if only voltage on one then I would suggest the sensor might be at fault.

 

[tricky]

imported post

Just to the rear of the battery

 

[tricky]

imported post

I am looking at a schematic for an 85 aspy, Brown wire comes from ignition switch TL2
If the licence light isnt working then there isnt voltage coming from the ignition switch because it (licence light) gets its feed before the tail light sensor. Double check the fuses. Power comes from battery to fuse to ignition switch to lights. if there is voltage at both sides of the fuse then check the ignition switch.