I have a problem of sorts - a 1978 245 with a wiring harness from 1989 and a 1984 instrument cluster ( I changed the dash ). The car has a 1993 5.0 L H.O. and everything is working except the gauges. It has been an on and off project but I am finally getting it finished, hopefully. I do have a shop manual for the wiring but it is for 1987-1988.It shows a wire going from position 'A' on the back of the cluster on the 4 pin connector for the gauges,( the wiring diagram shows it going to the fuse box and fuse 16 ) that wire is missing but like an idiot I inserted a spare wire into the connector 'A ' position and attached it temporarily to a red/white wire that was bundled in the same wiring loom. That I am sure was for the tach ( it was cut ) as although the gauges started to work there was also some smoke and I quickly disconnected it. With that setup the engine would not fire up and run. I noticed a resistor on the outside near the connector pins had been the culprit that fried. I do not have either the 1984 or 1989 wiring diagrams but since that 'A' connector pin position powers the gauges I am half way there! Any help would be appreciated very much, it's no fun when those two gauges do not work.