replacing old instrument cluster

[raycindy]

hi all raymond here from nz . decided to do up my wifes 1998 auto non mivec fto we got we got in about 2007 .but needed a new speedometer because couldnt read the mileage ,black marking on rectangular screen .i got one pretty easy through" beforward "awesome service same model number etc.the problem is ..when i took old one out there was a wire attachecd to one of the terminals on the back which came out of hole in behind speedo and i never took a photo.now i dont know which one .its one out of fourbehind the speedo dial on the back of cluster.markings are batt sp + - anybody know what that wire is for or what terminal it goes on.dont want to blame wife but she wanted to take apart and clean it, didnt take a photo when i told her .took 4 screws out and that was that. she also ruined cluster.
the next question is how do you adjust mileage reading of new cluster to the last known reading of old cluster .any help appreciated.thanks Raymond
also posted this on wtb instrument cluster but last discussion was back in 2013

[raycindy]

dont see any replies maybe query listed in wrong place.anyway installed new speedometer instrument cluster and all works fine thanks beforward so lucky to get exact model speedometer.rev counter sticks a little bit otherwise fine.rev c starts working normal after initial movement.about wire that was attached to either batt sp + or _neg on back of cluster;left it disconnected .didnt want to try it on anything incase it fused something badly.speedo cluster works fine with wire disconnected and taped up.the new odometer reading is 94000km instead of approx 160000km of old one.rang nz transport and they sorted it for me so all good to get wof .