truspeed question

so ive had a truspeed on my 02 since day 1. last year sometime my speedo would start to read on occassion. sometimes it will read half of my real speed or even less. most of the time it does not read at all. all other guages work fine..anyhow ive been told my instrument clluster is bad, ive replaced the vss on the pumpkin with no results. ive read where some have bypassed their truspeed and everything started working fine. so my question is will disconnecting just the power and ground be enough or do i need to connect the green and yellow wires together as others suggest? its been 12 yrs since i put this in so i dont recall what i did exactly but i know they are connected to the modules that sit on the driver side front fenderwell, at least thats where the green and yellow wired are attached to.