On a drive the other night a mate noticed that my rear left light spontaneously blew. On popping into ECP and buying a new bulb we found that the new bulb lit for a split second then blew again almost instantaneously.

 

I have since tried the old bulb as there was no sign of filament damage and again it shone for a split second before going straight out.

 

Now I immediately believe it's a bad ground somewhere caused by water ingress (happened after washing the car) but I cannot find the ground!

 

It could also be a bad circuit board on the bulb holder but I'm not 100% if this is a common issue?

 

Does anyone have a circuit diagram for the rear lights (Sadly i do not have a haynes yet) or does anyone know where the earth is for the rear left light?

 

Cheers all.

On a drive the other night a mate noticed that my rear left light spontaneously blew. On popping into ECP and buying a new bulb we found that the new bulb lit for a split second then blew again almost instantaneously.

 

I have since tried the old bulb as there was no sign of filament damage and again it shone for a split second before going straight out.

 

Now I immediately believe it's a bad ground somewhere caused by water ingress (happened after washing the car) but I cannot find the ground!

 

It could also be a bad circuit board on the bulb holder but I'm not 100% if this is a common issue?

 

Does anyone have a circuit diagram for the rear lights (Sadly i do not have a haynes yet) or does anyone know where the earth is for the rear left light?

 

Cheers all.

To follow up to this post it did turn out to be a brake light switch. I went for a febi replacement (highly recommend) and it fixed it.