KZ550 LTD Tachometer/Voltmeter gauge issues

Hello, I recently purchased a 83' KZ550 LTD (Title claims 84'). Not new to bikes, just new to Kaw and these forums...
Sorry if post is a bit long-winded.

The bike had obviously went down a couple of times in its lifetime, nothing major... tip overs + minor spills. A recent flop badly damaged the speedo. Engine is sound. This bike has the tach w/ built in voltage indicator. The only notable issues are the speedometer and center panel were smashed up including the voltage switch. New speedometer is on order, but decided to remove the damaged junk speedo and voltage switch while cleaning the dash area. Snipped the wires. The tach+voltage gauge were working excellent before cutting the wires.

Rigged a on-off-on toggle switch in the old voltage switches place in the meantime. This allows me to check the volts properly still using the switch. However, the tachometer itself is reading off around 3-3.5k rpms where it should be reading 1-1.5k rpms(needle still spins up). Any ideas? Did the factory switch have a built-in resistor or overlooking something else? Diagrams haven't helped much other than to lead me to believe that the cut Brown wire that went to the speedo has left a circuit open.

Any help is greatly appreciated. Thx

AND this should be tagged under electrical... sry

Most electronic tachs can usually be switched between two ranges. With a wasted spark system, the ignition is firing every 360 degrees of crank rotation on 4-cylinder bikes versus 720 degrees on many twins and singles.

I may have overlooked the switch then... I will take a look tonight.

No luck, couldn't locate any such internal switch (stock tach). Tried a few different connections, also tried resistors on the tach sense line, but that just halted the needle from climbing when throttle is applied. The voltage readout is normal when switched on that function... stumped.

Seems like maybe the harness could have been modified at some point so I'm open to other ideas if anyone has any? Thanks!

As to your original post, unfortunately, I have no idea...But for future reference, you might want to get out of the habit of "snipping" wires...pretty much everything in the wiring harness on these old gals is plugged together with bullet connectors or multi-pin plugs, allowing one to simply unplug/replace components...much easier to install replacement parts and greatly reduces time spent searching for electrical gremlins (potentially caused by home-spun splices)...Good luck with her!

Thanks for the advise... It's not a regular habit to do so, unfortunately there wasn't any saving the items "snipped" off in this case. All my new connections are being done properly using new bullet connectors, multi-pins, and proper soldering when needed. The wiring from the seat back was terrible, every wire was color swapped for whatever a PO had readily available, pink, white, etc. Needless to say, home-spun splices may have caused this particular gremlin. Can't be too upset... It was a screaming deal for the overall condition.

The bike is not beyond remedy, and coming right along one improvement at a time. The new speedometer and turn indicators have been installed and no complications are left regarding the voltage switch. Just that the tach still seems to read high. Extensive Internet searches have yielded no results. Still hoping somebody has maybe ran into it before... while I retrace my wires.