So there’s a weird thing going on with my tail lights. It’s quite hard to describe. 

 

So I had a short circuiting issue which I managed to identify and resolve with a genuine VW tail light assembly. It was the driver’s side tail light at fault. 

 

However, now, the following happens:

 

i) when the sidelight/taillights are off and the brake pedal is depressed, the passenger side and middle tail lights come on as they should, but not the driver’s side. 

 

ii) With the sidelight/taillights on, passenger side light is on as normal, but the driver’s side is on full-blast, as if the brake pedal is being depressed even though it isn’t. 

 

Any ideas? This seems a really weird one to me!

Welcome to the Forum.

 

First of all, I'm not sure which model you are referring to, also, there seems to be some confusion between rear lights and brake lights (or stop lights).

 

Whatever the model, the first check should be that there is a good earth connection to EACH lamp. Without a good earth, it is quite possible under certain circumstances, to end up with two (or more) lamps sharing an earth connection in such a way that the lamps become connected in series rather than in parallel as they should be.

 

Depending upon the model, when you say that 'the drivers side is on full-blast', it may well be that there is a wrong connection and the brake light (stop light) or the rear fog light (high intensity rear light) is receiving current, rather than the actual rear light.

 

As your replacement lamp is a genuine VW part, the connections and colours should be the same as the original.

 

I believe that the most likely scenario is that the rear fog light is illuminating, rather than the actual rear light, so I suggest that you try swapping the respective connections.

 

Regards

Just a guess... is it possible to accidentally fit a dual filament bulb  for brake and tail light so it bridges two circuits?

 

Say not fully rotated in the socket.

Sorry I should have mentioned it’s a 9n3.

 

The brake lights work by brightening the taillights, that’s if taillights are already on. The top bulb is a double filament bulb and the second filament is supposed to illuminate when the brake pedal is depressed. The fog light is a separate bulb altogether and that works just fine, when actuated by the headlight switch. 

 

I’ve checked the connections, cleaned them and reseated all the bulbs, and that seems to have fixed it, for now. Let’s see what happens!

Glad to hear that it at least appears to be sorted.

 

For anyone else with similar problems, I have (only once or twice) come across problems with new dual filament bulbs (Stop/Tail bulbs) where there appears to be an unintentional connection within the bulb itself, linking the stop light to the tail light - The only remedy is to fit another new bulb.

 

Regards