Passenger side ,side light problems.

Month or so ago, prior to MOT , I noticed that passenger side side light had failed. Bulb thought I, so one bought. Before fitting, I switched them on and light lit. Fabia gremlins thought I . MOT time, no light problems, but that pot hole I thought I got away with, had broken a spring and wrecked the top mount. Lately I've noticed that on sides, the light does not light.

Investigating further ,I've found -

Sides on- lamp out, but rear on- proving fuse on passenger circuit ok.

Dip on- lamp lit.

Dip +sides +ignition off and indicator to passenger side and lamp lights.

Lamp has now decided to light with just sides on, but I notice that output, IMHO is poor on both.

Could be just a bad connection at lamp, but in case I'm chasing a wiring fault ( loom damaged from pothole incident) ,or a bad earth ( though how a bad earth would bring on the lighting with dip, I can't imagine).

Anyone know how the front sides are earthed ( and where) ,if the wiring loom is separate for both sides and how run? Just in case ,I need to get meter ( or other wire tracing kit out) ,it would be nice to know how volts get from switch to lamp. ( i.e - is it down both sides or down one side and across the front.