I have a '92 Suburban that the speedometer has quit on. I checked the VSS in the transfer case and when moving I see about 8-9VAC on the system. Is there an easy point to get to to verify that the wires are good to the interior of the truck? I measure about 4.5MOhm across the plug to the front, but I do not know if that is right or not. I suspect that the wiring is breaking down due to age and such. I just don't want to pull that harness out if not necessary. Thanks!