EEC Power Relay Assembly reference page with part numbers 12A646…

EEC Power Relays
Ford Standard was replaced in F-series & Broncos in 1992 by ISO (International Standards Organization)/Bosch (now owned by Tyco).

The Ford EEC PWR relay connects pin 4 (B ) to pin 3 (load) when the coil is energized by pin 2 (trigger positive) having ~ 9~ 16V relative to pin 1 (trigger ground).
The ISO relay switches pin 30 (input) between pin 87a (NC; when the trigger coil is NOT energized) and pin 87 (NO; when energized) when there is ~9~16V difference between pins 85 (typically the lower voltage/ground) and 86 (typically the higher voltage/B ).

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Owner caption October 2017 · Photo 5640 of 6546