Ok that has helped immensely, and I now understand what it actually does.Thanks, and you're right, it is quite simple.

FFS. They're actually driving lights. I'm fair dumb aren't I? Anyway wired them up to check they work and they do. Promise I'll fit the relay tomorrow though; Too dark to try and find the right pins etc now.

Hi James.

Good move!

Since they are driving lamps, you'll want them going off automatically when you dip. So you'll need to take a spur off a wire going to one of the headlamp main beams. I don't know where the best place for this is, but I'd suggest it's close to the actual light switch on your column because it'll only need a short wire to then feed your driving lamp switch nearby.

The other end of your driving lamp switch will pass through your bulkhead (well protected with a rubber grommet) and go to pin 85 of your relay - this feeds the electromagnetic coil inside the relay which moves the relay contacts. The other end of this coil - pin 86 - goes to an earth. Turn on your headlamps AND your driving lamp switch and, 'click', your relay will energise... That's all it'll do 'cos you haven't joined the other wires yet

The purpose of these relays is to make the actual relay carry the heavy current to the lamps so the switch doesn't have to ( a switch would have to be a solid beast to carry this load on it's own, and to add the weight of these driving lamps to 2CV light switch - which is already on the edge with its own lamps - would be smoky...)

Mount the relay somewhere suitable - if there's a body or engine bolt that can be used, then all the better - you won't have to drill any holes. If the bolt is 'earthed' - as it will likely be - then place you '86' earth wire under this bolt too.

Then you just need a live feed from your battery - with an in-line fuse connected as close to the battery as possible - listen up; that's FUSE. CLOSE. BATTohsomeonehasalreadysaidthat... - going to pin 30, and finally a cable from pin 87 to your lamps.

Hopefully your lamps will automatically be earthed through their fixing bolts, but if not they'll need return earth wires going back to the car's body.

Make sure all the wires are secured at regular intervals, and extra protection added if there's any risk of them being scuffed through.

And it's easier to do than explain...

Thanks. Will complete tomorrow.

Right, hooked everything up. It works with relay in, BUT it dosen't go off when you dip and you can switch them on without any other lights on at all. Suspect I've wired something wrong. Any ideas? Printed off thoses instructions and followed them step by step, the only difference being it isn't an illuminating switch.

Thanks,
James

James, you may have wired up the feed to the fog switch to the wrong side of the main lighting switch. You needed to find the wire which was powered only when dipped beam was active and off when in any other mode.

Do you have dim-dip fitted to your car? That may jigger things a bit due to the reverse current malarkeys it uses to bodge the way it works.

James, does the relay go 'click' when you switch on your driving lamp switch?

Do you have a test meter or a test lamp on long wires? With either you should be able to tell which is the correct 'main beam' wire to use - you earth one end of the test lamp (or the -ve of your meter) and touch the other end to the column light switch and see which terminal becomes live when main beam is called for.

If you are absolutely stumped, you could always take a spur off one of the wires feeding the actual main beam bulb - just trace it from the wiring at the headlamp bar, find its colour, and trace it back in the loom until you find a location you can take a 'tap' from. This would then feed one side of your new driving lamp switch with the other end returning to the relay as before.

But I'd still look to take it from the actual light switch as it's near the dash.

Ventflaps may have a point with the dim-dip electronics, but I just don't know enough about it to comment.

This of any help?
< http://www.flickr.com/photos/30132857@N06/3624638437/ >

Dim-dip should have been disabled, but even if it hasn't, I don't think it would matter.
All that's being done is drawing a small amount of current from the main beam circuit to trigger the relay.

ken

Oh balls... Think I have connected it up to the main live wire looking at that. I was using a dodgy bulb 'n wire to earth and just chose the first one that was live when full beam was on. I think the problem has just been solved. Thanks.

Well,
that's today's work done, so time to trek off to the pub...

ken