I have an 87 Montecarlo ss that I'm putting a cutlass dash with rally gauges in. I got a wiring Harness from a cutlass with the sweep speedo. Found out the pins in the connectors for the clusters were different so switched them around using a guide I found on the internet. So I go to test the cluster and none of the gauges work just the blinker lights. My only idea is that the wires going in to the bulkhead from the firewall are different from the cutlass bulkhead I'm using. Can any one confirm this suspicion? If so anyone know where I can find the diagrams to sort this out?