You could need a wiring diagram, like I wrote earlier the pre diff lock Kodiak had a switch in the diff that earthed out when the 4WD was engaged, this fed a relay under the seat which switched the light on the dash. Suzuki 450s have a circuit board on the side of the 4WD/diff lock motor which can go bad. I don't know what your Kodiak will have. Because the engine management thinks the diff lock is in, it activates the rev limiter.