You are going to need a wiring diagram for both of those years to see if they are identical. To me, it sounds like the handlebar wiring or switch functions are different between those 2 years?
Without a diagram;..If you had lots of patience, you could test the switch functions and the wire colors to all the lights; but that can be difficult with all of the sealed harnesses and sealed connectors.
You should web search for a Suzuki motorcycle forum. We did the same thing on a Honda Quad for a charging problem. Took an hour of seaching a few Honda forums until finding a thread on the exact same problem. Then it took only a few minutes to fix it. We also found links to wire diagrams on those forums.