Main engine compartment wiring harness, not to be confused with the ECU Engine Harness. It fits 86 thru 91 because it comes with both style connectors, early and late, for the coolant level sensor and connects for either the Syncro or 2wd temperature sensor.

It includes connections to:
Temperature sensors (Syncro or 2wd).

Coolant level sensor (early or late).

Oil Pressure

Fuel pump relay.

Tachometer

Ground eyelet.

Air intake pre-heater

Circuit 15 power to fuel pump relays, fuse holder, and main power.