2004 R11S ABSectomy and everything was fine for 300 miles lost speedo brake lights

[valpor1100s]

I did a ABS ectomy on my 04 R11S and it has been great. The brakes are really good and I have put about 300 miles on it with no problems. About halfway through a 75 mile ride the speedo and brake lights quit working. I pulled everything apart when I got home and all the connections were tight and everything appears fine. Is there a way to trouble shoot the computer? I am really not sure what to do next.

I used this web site as a guide for doing the ABS computer part.

Removing the ABS moduel from my R 1100 S
http://www.karlsgarage.com/motorcyclepage/ABS_Delete.htm



Thanks
Ed

 

[pauls1150]

Have you closely examined your fuses? Fuse #1 (4 amps) will affect instrument lighting and the brake & tail circuits. If they are good, at least use a voltmeter to verify that +12V is getting that far, and track further in from there.

 

[valpor1100s]

There’s power at the taillight, the brake light doesn’t actuate.....
I’ll go ahead and check the fuse

 

[rogerc60]

It sure looks to me like there's a hole in the 4-pin part (that you showed in the close-up pic) where the magic smoke escaped. I don't have a schematic for that circuit but I would guess that's a power transistor or voltage regulator.

 

[gsaddict]

It sure looks to me like there's a hole in the 4-pin part (that you showed in the close-up pic) where the magic smoke escaped. I don't have a schematic for that circuit but I would guess that's a power transistor or voltage regulator.

Appears to be a power mosfet which would make sense for the brake light

https://www.mouser.ca/Semiconductor...tors/MOSFET/Datasheets/_/N-awhng?keyword=U320

The speedo gets its signal from the rear ABS senor IIRC on the later 1100S's (servo)

The part is most likely shorted and dragging the board voltage down. Replace the mosfet and the speedo will most likely work again as well.

Check your entire brake light circuit for shorts and replace the lamp before you re-energize the system.

 

[valpor1100s]

Thanks for the help .... feels like I finally have a path forward.