Hi,

Its been a while since I needed help! Car failed mot tonight on dip light not working and a weak rear brake issue.

So my main problem is this...
The pass side dip light is not working while the other side is ok.
The voltage going to it is 5.45v when it should be 12v.
I've went to the headlight relay but from what I can see it is feeding both dip lights and it seems to be perfect. I even swapped it over to another one I had and still the same problem.

I put a meter on both dip and headlight cable coming into and its reading 0.1-0.3v so I assume this must go to somewhere to get the full 12v... is there another relay or something between the headlight relay on the bulk head to the actual light. Maybe something under the dash?

I'd appreciate the help... or i'm just going to have to put a link cable from the working dip and I really don't wanna be doing something messy like that!

PS Hope everyone is well!!

Obviously there are many issues that could lead to this problem, but from my experience when its not the relay (oh, and please try a thirs one as a last result unless you are certain that the second is functioning perfectly without any doubt) most one sided headlight problems on Mk3's are either down to the earthing screw in the headlamp bowl, or what sounds more likely in your case the twist on cap on the back of the headlamp that you turn through a few degrees to remove and get to the bulbs themselves. These are pigs for going wrong and often you cant see what it is because of wire breakdown.

Make sure all earthing points are crisp and clean and greased to minimise corrosion.

Always remember as well to do your side to side swap tests - often identifies, but certainly eliminates as well.