I have replaced the entire cluster, pigtail and both sending units. The old cluster will not even allow gauges to be installed since there is no provision for them.
Problem im having is that the circuit board does not correspond with the dummy light version, ie where water temp gets signal on the dummy connector/board is not where it does on the gauge version, most of the wires color coating were the same, so it was easy just to verify function and then rewire
Everything is working, but I have 4 wires that are left over. 2 come from the 2nd Alt, but Im not able to tell which ones, there is a white wire that im unsure of, and also a black with red runner that im unsure of. I believe the 2nd gen used gray and a small brown
Hindsight, I prob would have added aftermarket gauges, but I want to keep the truck as close to original as possible to daily drive. I hate dummy lights because they only show the minimum, ie cruising with 20lbs of oil pressure is ok on the dummy. I want to have a better feel for what i assume

is happening.
Does anyone have a wiring diagram for the dash on these?
Thanks