I have an NP 231 mated to a 700R4. it may have come from an S-10, but I cannot be certain. There is NO connector under there for the speedometer. It has the sender in the transfer case, but since this was an engine swap the guy who did it removed a bunch of (supposedly) not needed wiring. Well I would really like to know how fast I'm going. So could someone help me with what these are supposed to do? I presume one is signal, one is ground and one is power. But which is which?