Headlight unit earth connection..

My right headlight unit has a very poor earth connection via the electrical socket that it connects to when it slots into position. I've checked the earth cable itself and there are no problems there, it's just the contact in the connector that's really poor and unreliable. I've checked the pins in the connectors and they all seem OK and not broken. Has anyone seen/resolved this before?

I think i understand the problem .. do you need to fit a new connection to the bulb as per the link ? https://www.amazon.co.uk/Holder-Hea...asc_df_B009XAAEA4/?tag=googshopuk-21&linkCode

Hi Demort Nope, it's everything in the whole headlight assembly, the indicator, headlight, dipped beam, side light that's only working intermittently. They all use a common earth which goes through the connector that at the back of the assembly that engages when the headlamp unit/assembly is pushed into the car itself. It's that connector that's not engaging properly and I'm asking for help on how to get it to engage better.

When you use the tool to engage the headlight - are you sure this is engaging correctly? I had an issue a few years ago where the sidelight kept flickering, changed the bulb and same thing. I had to carefully engage the headlight unit as it wasn't properly seated and worked loose.

Check that the bracket at the back isn't broken and pushing back. You can push it in manually from behind the lamp unit. MC

I have limited info at home but if xenon lights then the wiring diagram shows 2 separate earths .. one for dip/main on A12 and one for side lights / fogs on A6 USA spec as i have nothing else . I have nothing on standard lights . In short .. if the earth is fine its just the connection between the two that's the problem .. you can either replace the wiring connections in each plug .. down side is sourcing them or clean them .. we use an electrical cleaner which oxides the contacts so the Can says . if a female spade .. which one side will be then perhaps a screwdriver to close up the contacts a bit . Wiring plug in general and i remove it .. plug it direct into the headlight and see if it works .. that kinda says if its a bad location connection ... pushing the headlight in place and the plug not seating correctly . im probably wrong again but kinda working with no info and doing my best

I have 996 wiring diagrams Iain, I can email them over to you if you want them :thumb:

Thanks for the replies guys, I really appreciate them. Thanks Kris, but I've got the wiring diagram already. Thanks Demort - I've already tried electrical contact cleaner spray. I'll try removing the car-side connector from the bracket and pushing it on, seems like the logical next step. Thanks MC - I've tried that already - the bracket appears to be sound and it's a ballache to take out the wheel arch liner so I'm going to avoid trying that move again if I can. Thanks Fot0 - I didn't think of that. I use a 5mm socket on an extension to remove the unit but just push it back into place without using the tool. I'll try reversing the tool rotation and apply a little force to see if that helps.

You definitely need to use the tool to reinstall. You'll feel the assembly go overcentre and 'latch" into position. I'm surprised your headlamps haven't fallen out under braking before now!

I had some problems with mine for quite a while and I eventually found out the earth connector on the block inside the headlight had broken the earth. Its a tight fit where it is and I had to extend the wire a little to take the pressure off it once fixed, the gauge of the cables had put to much pressure/weight on the connector pin. I had to totally strip the headlight down, which was not particularly easy with no information of how to do this online and its extremely difficult un-hooking the yellow block connector inside the headlight, you can't get hands in so finger tips only. I think I ended up using 2 McDonald's wooden stirrers and a couple of small screwdrivers, while also sliding the purple lock out. It didn't look broken on initial inspection but it was just touching so only didn't work intermittently. But the clue was the angle it was at compared to the other connections? The connection had actually fatigued and broken once I looked further into it. Hopefully it is just the connection between the headlight unit and the headlight tray and not an internal earth like the above!

I forgot I wrote an FAQ about it, here it is in more detail. http://911uk.com/viewtopic.php?t=124477

Thanks Infrasilver - found your write up early on and it guided my initial investigations. It was very useful, and allowed me to discount the possibility of a broken pin similar to yours.

Hi Martin Apologies for bringing this one back to life, but what was it in the end? I have a fault on my headlights at the moment where main beam will bring on the indicator a bit and so on. A bit like you see sometimes when someone hits the brakes and all the rear lights come on dimly. I'm going to follow all the suggestions in this thread tomorrow. Berni

That is usually an earth problem