They both run off the same cable. All mechanical. My Massey had that problem and I had to remove the cluster, pull it all apart, found a broken spring and a broken plastic gear. Repaired the gear and sourced a spring from a junkyard where I found a larger tractor with a cluster that was already out but had a similar spring (but not quite identical). It now works. That was not a very fun job either. My hands and eyes are not as coordinated as they used to be. I kept wanting to use a hammer, and after a while thought about using fire to fix it. That's when I had to step away from it for a day or two.