xs650/xs1100 speedo convert

[redbone]

has anyone here ever put a 79 xs650 120 mph speedo onto an 80 1100. near as i can tell there is 4 wires on the 79, but only 3 on my 1980. i'm sure it is possible, but i'm just wonderin which wire from the 79 is not necessary.
any info appreciated
redbone

[bikerphil]

Looks like the extra wire is a ground for the reed switch. The earlier speedos had an additional blk/wht wire for reed switch ground and the later speedo shared the instrument light ground with the reed switch. If you have your turn signal self cancelling feature disabled, all you need is the 2 bulb wires. HTH

[fredintoon]

has anyone here ever put a 79 xs650 120 mph speedo onto an 80 1100. near as i can tell there is 4 wires on the 79, but only 3 on my 1980. i'm sure it is possible, but i'm just wonderin which wire from the 79 is not necessary.
any info appreciated
redbone

Hi Redbone,
I have that exact speedo on my XS11SE right now and it works perfectly.
As BikerPhil says, the wiring difference has to do with the signal self-canceller reed switch. Which I never even noticed as my self-canceller don't work after I replaced the defunct stock flasher unit with an electronic one.

[greatnw]

I'm swapping my speedo with the three wire connector for one with a four wire connector.. I'll pull the mini clips out of the connectors for a clean job, but do I need to ground the extra black white wire?

[bikerphil]

do I need to ground the extra black white wire?

Yes, I would ground the blk/wht wire if your'e using the self-cancelling signals. Tap that wire into the ground (black wire) for the bulbs.

[greatnw]

Yep, looked that way to me to and that is what I did.
Thanks, BikerPhil