Corroded wiring loom

[Pukmeister]

Went to start the bike for work this morning, dead, nada, zip. Took the VW instead. Tried again this evening and the instrument cluster rebooted five or six times with an a ESA warning which cleared. The bike started and ran. My GS911 showed fault codes with undervolts to the alarm unit.

Just had a look and found signs of copper verdigris corrosion on the air box on the left side next to the subframe. I exposed the inner wiring to find the main red power cable inside the loom rotted through. It had fretted against the air box allowing road salt/water in and it literally crumbled once disturbed. I now have to remove the fuel tank to expose more of the loom then cut and splice repair the main feed cable to the rear subframe. Luckily the bike didn't catch fire.

Will post photos later, kinda busy with fixing it now. Looks like I'm commuting by car for the next week.

 

[kyrano]

How old is the bike ???

 

[Pukmeister]

It's a 2008 GSA with ESA and factory alarm.

I've heard of wires chafing around the headstock area but not where the wires lay across the air box.

 

[kyrano]

Some of my jap bikes have had wires chafing around the headstock, and I had to cut and re-crimp/solder back together but not around the air box, maybe I should have a look over the weekend

 

[Pukmeister]

I think that in an effort to save weight and costs, they made the wiring looms short and cable tied too tightly in places.

Note the pics below, slight evidence of green copper powder staining as pointed out by the yellow screwdriver in pic 1 and the crumbled copper conductor of the red wire in pic 2. The red wire carrying the main power to the rear subframe components including ESA unit and Alarm/TPS unit will need to be exposed, the corrosion cut out and then replaced. I also found a slight trace of corrosion to the rear subframe just starting to form beneath the rear seat lock bracket rubbers so I'll sort that at the same time ( I was going to replace my clutch whilst at it but I just had to pay for my daughters car insurance renewal instead.)

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[Pukmeister]

Decided to pull the clutch whilst I'm at it, seeing as the fuel tank must come off to expose enough wiring. There goes another wedge from my holiday fund.

 

[MikeO]

I don't know the layout of a 1200, but it looks like you might have a rub point against the battery tray. Is it rubber mounted?

On the 1150 the main loom is routed under the battery tray on the LHS and the movement as it flexes on its rubber mounts can result in the loom tape and eventually insulation wearing away. I have protected mine now with a bit of tough plastic (a piece of chopping board) to avoid this recurring...

 

[Pukmeister]

Mike, it rubbed on the top rear corner of the air box, chafing through the cotton tape and the insulation. Salty water then got in as the bike is (was) my daily commute to work in all weathers, rotting the copper core of the wire.

I would advise 1200 owners to check where their loom runs close to the air box for similar problems.

 

[Bendy toy]

Oh yes.

You strip your bike to have the horrible 2008 paint dipped away and refinished. The dip strip only needs a few minutes the paint is conveniently very thin. When you get it back all nice & shiny the back frame slots neatly onto the engine. Then you find the airbox wont fit so its all got to come off again. Bolt the air box to the frame and refit to the bike. Oh dear the wiring is too shorts & has to be fitted BEFORE the frame bolts to the engine so it has to come off all over again. Oh how I laughed.
When eventually done, those wires really are scrunched into place. I was now so adept with a large Torx driver I took it off yet again and wrapped the frame with helicopter tape. It probably wont protect the wires but I feel better about having done a proper job.

All because BMW do things back to front and Team Frame don't talk to Team Engine and neither of them talk to Team Wiring.

 

[Pukmeister]

Thanks for the tip Bendy. Hopefully I will now only need to fit the rear subframe just the once.

I just got the new clutch components from Bahnstormer and I'm surprised at just how small it is for a single plate assembly that transmits 100+BHP. It seems a bit undersized for the job.

I'd expect something twice the size for the cost of the items.

 

[Bendy toy]

I wanted an RSR six paw clutch but I never got a reply. https://www.rbracing-rsr.com/bmw_clutches.html

In the end I stuck with the old plate which was still well within limits and funds were low.

BTW while its apart get the frame powder coated with a conductive zinc undercoat. It's certainly more hassle with the seat under tray etc having to come off but its well worth doing while the bike is stripped.

This seems to answer my RSR email issue but has some other interesting points to make
http://www.advrider.com/forums/showthread.php?t=551097

 

[Pukmeister]

I got the bike apart yesterday afternoon and the clutch looks almost new, with no obvious faults which is puzzling. The friction plate hung up on the splines when trying to separate the gearbox, but is a smooth sliding fit on the input splines?? I did detect a faint smell of gear oil sulphur when I removed the clutch pushrod but no sign of oil contamination to the clutch.

I shall fit the brand new clutch anyway now the bike is apart. Luckily for me the wiring corrosion has only tracked about an inch in each direction from the fault so should require minimal repair.

 

[MattW]

I got the bike apart yesterday afternoon and the clutch looks almost new, with no obvious faults which is puzzling. The friction plate hung up on the splines when trying to separate the gearbox, but is a smooth sliding fit on the input splines?? I did detect a faint smell of gear oil sulphur when I removed the clutch pushrod but no sign of oil contamination to the clutch.

I shall fit the brand new clutch anyway now the bike is apart. Luckily for me the wiring corrosion has only tracked about an inch in each direction from the fault so should require minimal repair.

Glad the repair won't be too much faff. Are you going to beef up the protection of the loom at that point?

It's always a tricky decision about replacing an otherwise good looking clutch (especially given the cost of BMW clutches) but I'm with you on this - once I'd gone to the trouble of splitting the bike, I'd change it if it had a decent mileage on it.

 

[Pukmeister]

Glad the repair won't be too much faff. Are you going to beef up the protection of the loom at that point?

It's always a tricky decision about replacing an otherwise good looking clutch (especially given the cost of BMW clutches) but I'm with you on this - once I'd gone to the trouble of splitting the bike, I'd change it if it had a decent mileage on it.

I've spent all day rebuilding the bike, she's now sat on two wheels again minus tank/seat/undertray etc. New clutch is 6.3mm, old clutch was 5.8mm.

I'm gonna repair the cable tomorrow and "beef up" the protection around the air box so it doesn't happen again, then complete the reassembly, bleed brakes and test ride.

 

[MattW]

I've spent all day rebuilding the bike, she's now sat on two wheels again minus tank/seat/undertray etc. New clutch is 6.3mm, old clutch was 5.8mm.

I'm gonna repair the cable tomorrow and "beef up" the protection around the air box so it doesn't happen again, then complete the reassembly, bleed brakes and test ride.

 

[Pukmeister]

Just realised I've been calling the rub point the airbox but it's actually the rearmost corner of the battery tray (which is part of the plastic airbox).


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