Fried ignition wiring

[jcteton@yahoo.com]

Anyone had their ignition wiring go up in smoke for no reason? Just got to the last day of a trip up the Oregon Coast. Pulled into the Hotel, room not ready yet so got back on the bike to get some lunch. Turned on the key lights came on, hit the starter, got a bump and all the lights went out, then started seeing some smoke coming up behind the cowling, jumped off the bike and switched off the ignition and smoke cleared.. After it cleared tried again to start, no lights nothing, thought the battery was dead, walked to an O'rielly auto parts to get a battery test..It tested fine..Called Sierra BMW service manager suggested the ignition wiring..We stripped off the shielding on the wiring only to find that the wires inside were melted and shorted together. So the bike finished the trip in the back of a U-haul truck delivered to Sierra BMW for diagnosis...Anyone have a similar problem? I asked the service manager if there was a service bulletin about this problem he said no..Still a mystery as to the cause..By the way its a 2004 R1150 RT, 62,000 on the odometer and always dealer serviced.
I was surprised that BMW doesn't have a fusable link or some other protection on that circuit..I suspect wire routing and eventual problems.

 

[dieselyoda]

Year and model would help but I see you have a bunch of stak-ons. I'm gonna guess your electrical load through those wires is unprotected and exceeds the current capacity.

 

[pauls1150]

Haven't seen ignition wires melt (on a BMW, that is...), but I've seen other harness areas fry, usually due to an owner's short between the headsets or a pinch between frame and/or body panels...

 

[CNRed]

Well, the smoke leaked out for a reason...
I had an R100gspd wiring harness go up in smoke a few years back, the entire harness melted. The problem was caused by a wire that was in the harness that was supposed to power a clock that my bike did not have installed. Wire shorted to ground, melted the insulation and insalation of all the other wires around it. Resulted in about a new $350.00 main harness and about 7 hours of work,(i work slow), alot of burnt wire smell and a ugly feeling in my stomach watching my old Airhead go up in smoke....

 

[gsaddict]

You need to find the source of the short - chafing to the frame etc.

There are several unfused circuits on the oilheads. Following the schematics will expose this flaw.
I brought this up with BMW Canada years ago and was told they have never had a problem.
I have since repaired many including the F's
The fix is to dig into the wiring and fusing the Ignition feeder (@10A) as well as the load relief feeder circuit (@20A)
Search out some threads on ADV Riders for a how to.

Hexheads are worse - I bought an '08 1200GS insurance writeoff due to wiring fire.
Upon rewiring/checking the schematics I found that NOT 1 battery+ feeder is fused!
I don't know what BMW was thinking (or not)


A couple of pictures on fusing the R1150GS