My bike has been running with no back light for some time now and I need to fix it as MOT is due soon.

I have a non-standard SDR light unit that has integrated indicators and rear light and this has been fitted for about five years now with no problems. As many of you will know when you need to remove the tail unit you have to unplug the white connector and, (for my unit), two indicator bullet connectors. I can't remember the original wiring set up before I fitted the integrated light because it was so long ago.

Anyway, the unit now works for the brake light and the indicators but there is no rear light when the ignition is on. The front headlight works fine, both dip and main and pilot bulb. It's just the real light. All fuses are OK.

This morning I noticed that it looks like one of the wires that attaches into the rear of the male white plug, (on the bike side, not the tail unit side), is missing. SEE PHOTO

I have cut away the plastic around the terminal to see if there is a broken wire end and it looks like there is but I cannot find a corresponding wire hanging loose in the back of the bike wiring that is immediately obvious as the broken wire. I don't know whether this is my rear light problem or not. One side has two green/white wires and the middle has a white wire.

Does anyone know what coloured wire should be coming out of this white connector or in fact is there no meant to be one?

SDR standard connector to rear light unit is a white, brown and green/white wire three pole connector so not clear how yours works - have a spare OE unit available for loan if that helps re MOT.

In the picture you can see another two wires just to the right of the white connector.

It's a bit complicated to explain but a few years ago I needed to splice in a power lead and earth to run a rear view camera I was playing about with. The two female bullet connectors you can see are the spliced in wires. The red bullet connector is spliced to a brown wire and the black bullet connector is spliced to a white wire. I don't use them anymore but what is odd is that the two ends of the brown and white wire are bare and don't go anywhere.

I suspected that one/or both of these had broken off the white connector so I tried fixing the white wire to it and immediately blew the 15 amp fuse in the box. I didn't try the brown wire because i had no spare fuses if I blew another one.

Maybe I should have tried the brown wire instead if the third terminal on the box is meant to have a brown wire coming from it?

If anyone could take a photo of the wires coming out the back of the white connector it would really help me. No.47, is it meant to have TWO green/white wires out of one side? It's always been like this.

OE is just one white/green - have a look at SDR wiring diagrams on pages 13-50 and 13-55 of the repair manual - OE set up = three wires for rear light and two for each of the indicators - guessing that your single connector needs to have the OE wire set-up plus one wire at least for each indicator (assuming shared power wire) but that would mean a five pole connector required- no idea what your extra green/white is for - does it come off the main loom? Do your indicators work?

I'm no electrician though as you can tell from my ongoing issues described here.........................................

PS - the OE connector wire order is white/green, white and brown vertically from the top as per your connector in the photo - given that you have a doubled up white/green, could it be that you've lost one of the doubled up white wires to the central pole and a single brown to the bottom pole of the connector? Can't see how that provides connection for the indicators though.

No.47 Mate.

I forgot to say but last week I had another look at the wiring and non-working back light.

I tried the combination you suggested, doubled up white/green, doubled up white and the brown on it's own.

Worked a treat. Everything back to normal now.

Cheers.

Mine's a Guinness......