Left Switchgear Wiring

[tngarren]

2021 R18 Classic

Seems I fix one thing and break another. I had to replace the plastic cruise controls bits on left hand switchgear. Now the cruise control works but I lost function of turns signals and horn. The four buttons on the lower portion of the switchgear. There are three wires on the connector - yellow, brown, red/green.

I'm no electrical expert and could use some advice on which wire(s) control the turn signals and horn. Also, how I might test continuity to the wire if the button is pressed.

Thank you.

 

[tngarren]

Please correct me where I am wrong as I think through this. I'm thinking the three wires to the left switchgear are CanBus, so one is 12V power and the other 2 are Can low and Can high. If the other buttons on the left switchgear work (cruise control, headlights, flashers), the Canbus wiring must be good and the problem is with the signals and horn buttons. Then why would those four buttons stop working a the same time.

 

[tngarren]

My apologies if I am over posting on this. I measured the voltage to ground in the 3 wires going to the switchgear. The yellow and brown wires have 7V and the red/green wire has 12V. This is as expected according to ChatGPT.

I also disconnected the battery to let the control units reset. Did not help.

 

[tngarren]

So much for ChatGPT. Someone on the GS-911 support forum said 7V to ground on CAN bus is not normal and that it is likely a LIN bus. Now ChatGPT agrees. Good grief. Now I need to learn about LIN bus.

 

[tngarren]

The left-hand switchgear is a LIN bus. The 3 wires are 12V, ground, and LIN data wire. The LIN data wire read 7 volts with ignition on. I think that is due to the LIN data signals fluctuating between 0V and 12V so frequently that my multimeter read 7V.

Anyway, I replaced the lefthand switchgear and all good now.