1990 Ford Bronco Instrument Cluster Wiring Diagram 60-1 - Gas with Tachometer

This document is page 60-1 of a Ford factory wiring diagram set, showing the Instrument Cluster circuit for gas engines equipped with a tachometer. Power enters the cluster from fuse 18 (15A) in the fuse panel, hot in start or run, via circuit 640 R/Y through splice S215 and connectors C251 (pin 5) and C250 (pin 13). The cluster contains the engine warning indicator and module, fuel gauge, coolant temperature gauge, oil pressure gauge (with a 20-ohm resistor), tachometer, and volt meter. The fuel gauge circuit (29 Y/W) branches for single tank and dual tank configurations, with F-Series and Bronco-specific connectors (C206, C202), leading through circuit 673 DB/Y to the fuel gauge sender/electric fuel pump (145 ohms full, 22.5 ohms empty). The coolant temperature sender reads 74 ohms cold and 9.7 ohms hot on circuit 39 R/W. The oil pressure switch (closed with normal oil pressure) connects via circuit 31 W/R. The tachometer receives signal on circuit 648 R/LB from start/ignition and uses circuit 398 BK/Y for 5.0L, 5.8L and 7.5L engines (not used on 4.9L). Grounds shown include G100, G201, S103, and S200, with cross-references to grounds pages 10-1 through 10-11 and related pages 12-3/12-5/12-7, 20-5, and 49-2.