1150GS Side Lights not working...

[John Leah]

My 2002 1150GS had been sat unused since August but with BMAD this weekend and weather improving I thought I'd better get it back on the road so booked an MOT for this afternoon.

This morning I parked it on the lawn and gave it a good clean and checked it over. Problem... rear brake light not working - bulb OK as front brake lights it so suspect the switch. Removed it, cleaned it but still no joy so ordered a new one from Motoworks.

Got to the MOT and, not surprisingly it was spotted but the nice mechanic accepted that as I had a new switch on order it would waste everybody's time to fail it on that. Good man!

Then he spotted the side lights weren't working! Bulbs OK, fuse OK so suspected the handlebar switch but a spray with contact cleaner didn't make any difference so he had to fail it after all.

Got home and removed the handlebar switch cluster to get better access to the contacts yet a liberal spraying direct into the back of the switch made no difference. This stumped me so I suppose next step is to trace the wiring but as my DVM is broken I can't do that today.

Also, which may be related, is that the ABS lights flash alternately - did I read somewhere that side light failures can upset the ABS diagnostics? I have had occasional ABS flashing problems but always put this down to low battery voltage as stopping and restarting after having ridden for a few miles always cures it. Note: Brake fluid changed year before last and about 3,500 miles ago so intended to change again this year.

Dodgy switches are perhaps hardly surprising as about the only use I had of the bike last year was to tour Ireland... in the pouring rain!

So, can anyone suggest why any of this may be and could any of these issues be linked?

Cheers,
John

 

[Steptoe]

Side lights not working can be a sign of a broken wire in the ignition loom, the short section that runs from under the ignition unit.

 

[John Leah]

Thanks Steptoe, I'll take a look at that.

It seems odd that all three electrical faults should appear after a few months without use (bike was fine when put away) so could the brake light and alternate flashing ABS warning be replated to the side light issue?

The new brake light switch should arrive today so that will help in understanding: if it fixes the brake light then I'll know it's not related to the other two. If it doesn't fix the brake light...

Cheers,
John

 

[Ian J Hartley]

Steptoe has more or less nailed this for you, but I will explain in more detail.

The power for the side lights comes from the battery via the ignition switch. The ignition switch has two wafers, 1 in park (fully anticlockwise) the other in 'ON' fully clockwise. There is a link inside the switch. But both wafers feed the same small gauge green wire which runs from the ignition switch to the rear most contact of fuse 2. The power then goes through the fuse out of the forward fuse contact and then splits off going to the rear tail light and the front side light.

If your ignition harness is tywraped to the frame and not able to flex freely then the most likely place for the fault is in the ignition harness (broken wire). Most people have cut off all the tyraps on this short loom to allow it to flex easier.

The rear tail light is a twin filament bulb with the brake and tail lights sharing the same earth. However, the ABS monitors the rear lights and warns if there is a malfunction.

This doesn't explain why your brake light does not illuminate, when you press the levers, unless you have two seperate faults. A poor earth here would explain brake and tail but would not explain the front side light inop.

I take you have tried flexing the ignition harness to see if you can get the side lights to flicker.

 

[John Leah]

Thanks Ian,

That helped a lot and I now understand the inter-relationship between the rear light and ABS which explains the 'new' ABS fault and that fixing the light will fix the ABS.

Starting with the brake light though... I fitted a replacement switch today and the brake light works again proving it was the switch at fault so coincidence and unrelated to the side light issue.

The side lights are still a problem, however. I cut all the ties and flexed the cables but this made no difference. So, I need to gain access to the loom and the starting point should, I suppose, be the ignition switch - but only if I can gain easy access there. Does the loom terminate at a socket that the ignition switch plugs into that I can test from? Or, would I be advised to take a different approach?

Cheers,
John

 

[Ian J Hartley]

Good news about the brake light.

The ignition switch harness terminates at a 8 way orange connector, left hand side of the headstock. But you have to lift the tank to get at it.

Without a DVM, you fault finding is going to be awkward. You could try removing fuse 2 and jumper a positive wire to the forward contacts of the fuse holder. If your lights come on then the fault is highly likely to be the ignition switch wire.

Good luck.

 

[Steptoe]

Thanks Ian,

That helped a lot and I now understand the inter-relationship between the rear light and ABS which explains the 'new' ABS fault and that fixing the light will fix the ABS.

Starting with the brake light though... I fitted a replacement switch today and the brake light works again proving it was the switch at fault so coincidence and unrelated to the side light issue.

Ians advise about the brake light abs warning is only relevent for post 2003 bikes with servo brakes - the earlier ABS system i.e. yours, doesn't have any connection between the rear light and the abs system, as you've now found out.

 

[John Leah]

Thanks guys, all help and advice gratefully received!

I'll whip the tank off over the weekend and check from there.

I'll worry about the ABS when I have the lights working then, all the while keeping fingers crossed it's just a low battery.

Cheers,
John

 

[Ian J Hartley]

Have you tried this:

Remove fuse 2 and Fuse 3 with the ignition OFF jumper the rear of fuse 3 to the front of fuse 2. Your lights should illuminate.

If they do then the fault is in the ignition harness.

If they don't. (and your battery voltage is good) then the fault lies else where.

This jumper links the battery straight to the side light circuit.

 

[Steptoe]

Have you tried this:

Remove fuse 2 and Fuse 3 with the ignition OFF jumper the rear of fuse 3 to the front of fuse 2. Your lights should illuminate.

If they do then the fault is in the ignition harness.

If they don't. (and your battery voltage is good) then the fault lies else where.

This jumper links the battery straight to the side light circuit.

That's worth knowing

 

[John Leah]

Thanks Ian, that sounds like a top tip. Been away for the day but I'll try it first thing in the morning.

Cheers,
John

 

[John Leah]

I suppose it was a bit optimistic to think I could play with my motorcycle over a bank holiday weekend when SWMBO had so many 'fun' things she wanted us to do. Therefore it was only today that I was able to hide in the garage and conduct this test.

Result: lights lit so next step is to delve around under the tank. Oh, get some new leads for my DVM first would be useful!

Thanks for the advice.

Cheers,
John

 

[Ian J Hartley]

Well done. Progress.

Steptoe nailed your problem in post 2 so credit goes to him.

You will likely find a broken wire in the harness. You may be able to repair in situ if you feel capable, or replace the complete assembly.

Here is a link that might help. Some of the sub links might also be helpfull.

If not do a search. This has been a common failure.

http://www.ukgser.com/forums/showthread.php?t=214151&highlight=R1150+ignition

Good luck

 

[John Leah]

Those links and advice given were very informative and certainly pointed me in the right direction so thanks for that.

It took a few days to find a big enough slice of time to devote to this as I wanted to work methodically through the loom without risk of having to stop once I'd started.

So, this afternoon I set to it. I'd already cut cable ties but still managed to find a couple tucked away under the tank and with these removed I had good access to the switch end of the ignition loom. At this point I still hadn't removed the tank as I wanted to see what happened when I was able to flex the cable... nothing was the answer!

What did turn the lights on, however, was to apply upward pressure to the base of the switch.

I slackened the grub screw, pulled out the switch and, without disassembling it, sprayed contact cleaner into an many holes as I could find. Result: the lights stay on and no amount of flexing the cable or pushing the switch will make it fail. Conclusion: water had got into the switch during my soggy tour of Ireland last 'summer'.

But I have to ask... is it that simple or does the cable have a break that I've inadvertently, but temporarily, fixed?

I think what I've read has convinced me that I still need to buy a new loom if only as insurance against the inevitable but that can be next week - tomorrow I want to get it re-MOTed.

Oh, I've also learned how easy it is to steal one of these as, provided it's not locked, who needs an ignition key? Nice one BMW!

Cheers,
John