ECM Power And Ground Circuits Wiring Diagram (1988 4.9L, 5.0L, 5.8L Ford F-Series Pickup)

  • By: Abraham Torres-Arredondo
  • Created: 09 July 2025
  • Updated: 10 July 2025
  • Articl Id: 716
ECM Power And Ground Circuits Wiring Diagram. EEC Power Relay Circuit Diagram. (1988 4.9L, 5.0L, 5.8L F150, F250, And F350 Pickups)

APPLIES TO: This simplified ECM power and Ground circuits wiring diagram applies to the following vehicles:

F150:

  • 4.9L L6 Ford F150 Pickup: 1988.
  • 5.0L V8 Ford F150 Pickup: 1988.
  • 5.8L V8 Ford F150 Pickup: 1988.

F250:

  • 4.9L L6 Ford F250 Pickup: 1988.
  • 5.0L V8 Ford F250 Pickup: 1988.
  • 5.8L V8 Ford F250 Pickup: 1988.

F350:

  • 4.9L L6 Ford F350 Pickup: 1988.
  • 5.8L V8 Ford F350 Pickup: 1988.

This wiring diagram includes the following circuits:

  • EEC Power Relay.
  • EEC Module Grounds.

EEC POWER RELAY TESTS: Use this guide to find out if your no-start is caused by a bad EEC relay.

WHERE TO BUY THE EEC POWER RELAY: Need a replacement EEC Power Relay? These are two are from known automotive brands I’ve personally used on customer vehicles with great results —dependable and plug-and-play.

Your support through these links helps keep this site going and lets me keep publishing more diagrams and free how-to content. I really appreciate it!

EEC Power Relay Circuit Wiring Diagrams

More Ford F-Series Pickup Tutorials

You can find a complete list of Ford F-Series pickup wiring diagrams and tutorials in this index:

Here's a sample of the tutorials you'll find in the index:

Thank You For Your Donation

If this info saved the day, buy me a beer!

If This Info Saved the Day, Buy Me a Beer!