Michael Lewis

One more issue before I leave you guys alone lol
1987 f150 xlt lariat, 5.0, aod

Not getting power to the fuel pump relay. Decided to test the eec relay. Got out my DVOM and have power going to it. Testing for ground I hooked up my negative lead to the battery, set the meter for continuity, and backprobed the black wire at the back of the EEC relay connector. I got continuity to ground but only when the key was off? Thinking this may be why my truck isn't starting but if I don't have it done tonight it's getting towed to impound when my landlord comes out in the morning to spray for weeds.
so I guess my question is, shouldn't I have ground at the relay at all times? And where can I look next as to why I only do with the key off?

raski

You shouldn't be checking circuit continuity with any power applied(battery).The relay coil should have battery voltage applied and the EEC should ground one side of the coil when you turn the key on, energizing the relay. The contacts close and should send power to the fuel pump.Because if its environment, I would first make sure you have good, clean connections at the fuel pump.

Steve83

Click this & follow the links in the caption:


(phone app link)