Headlight problem?

[captainsmelly]

I'm a bit puzzled by this. I turn my headlights on, and they both work. Briefly. The offside light very quickly dims to a side light glow, while the near side stays as it should. I've changed the bulbs, and tried jiggling the wiring as well as cleaning the connector into the light. No joy.
Makes no difference whether engine is on or off.
MOT next week.
WHY?!

 

[John Sims]

Bad wiring. There must only be the smallest of connections left somewhere which is heating up as you try to put too many amps through it. As it heats up its resistance increases and the lights dim.

 

[bmnelsc]

It does sound like a bad connection somewhere. I'd be looking at the connector - specifically where the wires join the metal connectors inside the plastic connector. There are tools that enable you to push the individual wires out of the plastic part so you can examine each one in detail.

 

[Mike_Pollock]

I'd guess the wiring rather than the plugs as jiggling the connectors has no effect.

Best to just replace the last 20cm to the bulb with new wires, and a new socket to the bulb.

 

[captainsmelly]

Bloody crappy german electrics. Going to bypass the original wiring to the bulbs altogether, use a pair of relays switched off the existing feed to the dip and main beams to switch a high current circuit straight to the (uprated) bulbs. Did this to a capri a few years ago and the improvement was stunning. I'll also polish the lenses whilst I'm at it.

 

[Buddy]

Replace enough wire to get beyond the hinge area as the constant flexing of the wires in that area is usually the cause of this type of problem and make sure there is plenty of room for flexing.