'00 R1100S burning smell NO FUEL PRIME NO START issues

[pepeklaus]

I smelled a burning plastic smell before my r1100s broke down on the side of the road. I traced the cause of the burning smell to the wires from the right handlebar kill switch that plug to the righthand side relay box as shown in photo.


The current symptoms of the bike are no start and no fuel prime. I checked first for fuses and only 1 was broken. A 4amp fuse for the rear light I think. Next I checked for the starter relay and I confirmed that it was not working. So that is probably the cause of the no start.

The no fuel prime issue is more difficult to diagnose. I swapped the horn and load relief relays with the fuel pump and motronic relay and I still had no fuel prime. I then jumped the fuel prime relay by inserting a wire to pin 3 and pin 5 and the fuel pump worked. I think that rules out any continuity issues with the fuel prime. I also swapped out the motronic unit with a spare one that is known to be good and still got no fuel prime. Am I correct in assuming that power from the battery stops somewhere between the ignition switch or the handlebar kill switch according to the electrical diagrams?

Have I ruled out all other possibilities?

 

[senseamidmadness]

My first suspect with the "no fuel prime" issue would definitely be that melted wiring to the handlebar kill switch. I think you're right and that switch interrupts fuel pump power.

Folks with much more electrical experience than me will probably chime in as to whether this was caused by the dreaded "unfused positive leads in the electrical box" issue. I know there are at least two circuits on most Oilheads that don't have fuses, and when they go over-amperage this kinda stuff happens.

 

[jrogers]

I chased a no start problem on my 04 R1100S BCR for 7months. It turned out to be the start/kill switch. Cleaned it with contact cleaner and now there hasn't been any issues for months.

 

[pauls1150]

Do you have a big clear schematic to work with?
This page has one for the 1100RT, but the S "should be" similar...
https://www.mac-pac.org/tech/electrical-diagrams/

 

[gsaddict]

The melted wire is the feed for the lighting circuit.
The Grey/Blue wire comes from the ignition switch to the Hi Beam switch LHS and also feeds the headlight switch RHS (euro models) and the High Beam indicator.
This circuit is unfused.
Any short to ground or overloaded headlight circuit will result in melted wiring.

It is very likely that the short affected other wires in the harness including the ignition circuit.
Digging deeper and opening the harness is next.

Here is a picture of an '08 1200GS I repaired. This was caused by an unfused wire shorting to ground.
Mice were to blame. BMW continues to leave their + feeds (red) unfused.

 

[gsaddict]

Do you have a big clear schematic to work with?
This page has one for the 1100RT, but the S "should be" similar...
https://www.mac-pac.org/tech/electrical-diagrams/

It better to refer to the correct diagram.
There are enough differences

 

[glenvine]

No start

Clymers has pretty good wiring circuit diagrams; you just have to wade through them to find your model.

You may have checked this out already: the kick stand has a kill switch micro switch. On a functioning system you can turn the key to the start position and cycle the kickstand. The pump can be heard pressurizing for about one-second when the stand is retracted. Just like cycling the kill switch. If the side stand switch is not working I think it may be be just be part of the no-start problem as the melted wires seem to be culprits as well.

I have encountered an overloaded fuel pump blowing a fuse. Usually this occurs on a bike left with gas in the tank for a year or more. So if you were running the bike regularly, gooey gas freezing the pump’s motor is probably not part of the problem. The hoses in the tank can spring a leak but you should still hear the pump running.

Chevron’s Techron is magic. Use it at least once a year in anything with fuel injectors.