Wiring Loom

[rick]

Has anyone else had the wiring loom short out to the frame?

Mine's gone on the feed to the ABS unit on the right hand side under the tank.

Has made quite a mess of the wiring. Dealer is saying new loom. The ABS stopped working, but the bike was still running when I got it to the dealer, a bit rough, but still running. In fact it wouldn't stop, even when I took the key out.

Now if the bike had some fuses they would have blown, probably preventing alot of the damage that has occurred. I'm lucky it didn't catch fire.

The bike is an 05 standard 1200GS.

 

[Dahoum]

My wiring loom was replaced last year after causing what seem like similar problems to yours with the ABS.

It had apparrently worn on a bracket but the dealer did not specify where.

They said as it involved ABS wiring the whole loom needed renewing.

As they considered it a buiild fault they (BWM Battersea) did it for labour only even though the bike was well out of warranty. Damn glad they did too - a new loom costs over a grand

 

[rick]

Thanks for your reply. Sounds like the same thing to me.

Did have a look at where it happened and there's a flat piece of metal that the loom goes over. Probably a bracket for something or other. Didn't have my camera with me at the time.

I certainly consider it to be a build fault and in my opinion a loom should never short out against the frame, certainly not on a bike which is less than 4years old. I'd also like to know why the ecu continued to power the circuit for so long to cause the wiring to melt like it has.

I'm still waiting to hear from the dealer, but my guess is that they will be trying to do a similar deal. I'm not sure I should have to pay anything to correct a build fault though, in warranty, or not.

I was told a new loom is £600 at the dealers, perhaps they've come down in price. I have done some research, Motorworks have secondhand looms for £195 and there is also a guy on ebay who has several looms for £135 each posted. I'm beginning to wonder whether it's worth keeping up the full service history.

 

[iceclimber]

Blown Wiring Loom

Hey guys,

this has just happened to me on my New Zealand new, 2005 1200GS.

Big puff of smoke from under the handlebars when starting it one afternoon, the bike then dead except from some sparking sound when I turned the steering. Absolutely no warning of this prior, totally out of the blue !

The wiring loom runs from under the tank through the forks head & up to the handlebars. On the way it runs over the top of a flat bracket that the horn is fixed to. This is where the loom wore & the wire blew ! The loom had not dropped at all and was still very firmly in place held by the original cable clips. It was caused by 4 years of light rubbing on the horn bracket. Design flaw or what !! my god they've been building these boxer BMW's for more than 60 years ?? you'd have thought that they'd have worked out how to stop this happening ??

I have picked the loom apart at the damaged area & located the damage. It is the 0.75mm red cable that is the live feed to the ignition switch. It blew the wire appart like a fuse and has burnt the insulation off (i've exposed about 100mm of the loom) The motorad guy in Wellington suggested that this will be the case right back to the source point of the wire due to the heat generated. He loaned me the wiring CD & from the drawings I can identify the connector block it will go back to.

According to the motorad guy i'm lucky as i've managed to start the bike & run it OK for a few minutes by clipping a patch wire across the exposed & blown section of wire, proving that none of the control units have been damaged !

So what to do next ? 4 years old. 45,000 kms & 2nd owner i've got no chance of BMW coughing up towards it.

I'm planning to get the tank off and have a look and see if I can locate the connector block & then run a new feed wire in parallel with the loom

A new wiring loom here is $2500 plus labour to fit, so approx $4000 !!

If anyone has some advice then I would be very happy to hear from you.

Not sure I love BMW's any longer

cheers
Steve

 

[Pukmeister]

Why not get a replacement used loom posted from UK to NZ from Motorworks, James Sherlocks or similar? Postage shouldn't cost much for used parts, and a loom can be packaged small enough to cost less. Providing it is guaranteed by the vendor you should have no worries, the bikes various controllers should be plug and play into the loom?

Obviously with the larger UK/European market there are more bikes hence more breakers and more choice compared to Aus/NZ.

Glad to hear your individual controllers are undamaged by the faulty wiring.

If it were me I would do my own loom cable repair, but I used to do a lot of control circuit and high power wiring in the past so can do a quality job. If you have good quality terminations and use adhesive filled heatshrink it should be a permanent repair solution providing the cable is rated to the original design capacity. By the time it is wrapped in loom cloth tape you'd probably never guess it was repaired.

Thanks for the detailed description of the fault, just off with a torch to check my 2004 bikes loom.

 

[Supertech]

i've stripped down looms on other bikes and replaced wires. Its usually possible to do this, but sometimes you have to go way past the damaged point so you can splice in new wires with out making a bulge in the loom at a point where you could least do with it. In the uk Vehicle wiring products supply all the right sort of materials you need for this.

If doing this use line line crimps with heatshrink, and not solder. Bind the loom with loom tape, not insulation tape that turns into a sticky mess. If its a problem area you could get some PTFE spiral wrap and put it over the loom in this area before it happens or after you've made a repair.

 

[iceclimber]

Many thanks for the replies,

I will be attempting to do the repair myself & install a new core (single 0.75mm). I'm OK with electrical stuff it's the mechanical stuff that frightens me ..... so my biggest concern at the moment is removing the fuel tank & any other major parts that need to be yanked out of the way to get at the wiring !

I'm also going to contact Motorworks re: a new Loom, but I couldn't really contemplate fitting it myself !

BTW ..... the hot pies are pretty good in NZ, especially the steak & cheese !

cheers
Steve

 

[Pukmeister]

Removing the fuel tank is easy, no need to remove the coloured tank cover, alloy side plates or alloy fuel filler neck. It takes 10 minutes:

Remove seats. Take big tank plastic side covers off (Dzus clips).

On LHS of bike, remove the round black plastic cover (if fitted) on top of the fuel pump housing. Unclip the fuel pump wiring connector and fuel tank level connector wiring (using a small flat screwdriver to release the retaining clips). Unclip the self-sealing fuel supply pipe.

On RHS of bike, unclip the self sealing fuel line and pull the two soft rubber vent/breather pipes off.

On the top coloured cover, one small Torx screw each side to remove, on the top leading edge of the coloured tank cover where it joins the beak.

The tank is held on by four allen bolts:

Two allen key bolts hold the tank clamping brackets to the frame underneath and to the rear so remove these.
Two more allen key bolts to slacken (but leave in place) at the front edge of the tank.

Once these are undone, lift the tank up at the rear and slide it backwards then lift off the bike with its coloured tank cover and small alloy panels still fitted.

Easy.

Obviously best done when the fuel is nearly empty.

 

[iceclimber]

Hey thanks Pukmeister,

I'm getting ready to take this investigation to the next step .....

BUT Can anyone advise the following ......... Once i've got the tank off ..... From the wiring diagrams, the connector block that i'm going to need to locate is ref: X9430 - ( which according to the wiring diagrams is gonna have at least 5 'reds' connected to it ) I've got a sneaky feeling that this block may be burried under the main computer/controller units
If so, and if I need to, what are the implications of unpugging these units for short periods ? I imagine there must be some ?

Steve

 

[Slowdown]

If oyu're going to be working on electrics I'd recommend you disconnect the battery. Then removing any/all connectors won't cause any problems.

Take pics if you have to 'un loom' any wires so you can be sure everything goes back in the same place. You don't to introduce any new stress/pinch points!