[jww]

Working on my brothers’ 98 GMC p/up.. 5.7 gas, auto, 3/4 ton,, etc. 91k miles.

He drove a short distance a month or so ago. Went into a store and on leaving truck would crank, but no start. On coming home from FL couple wks ago I find it in my driveway waiting for me! LOL !

No hum from in tank pump and a little spray in throttle body made it wanna fire. I’m thinking new fuel pump.
Checked for power before raising tank/new pump back in place and no power on the gray pump wire.

Changed to a new fuel pump relay but no bueno.
Cleaned a bunch of grounds, still no juice to pump.

Checked under hood fuse block and I have constant 12V power on pin 87, ( key on and key off) jumping pin 87 to pin 30 (gray wire) and have power to the fuel pump with key on and off.
Pin 86 constant ground .

I believe pin 87a has to close with pin 85 to make pin 30 hot only with switch on. Of course with the jumper I have now 87>30 pump has constant 12V.

I’m electrically challenged but can anybody explain in simple terms what it takes to close the electro magnet inside this relay to make pin 30 hot as it should??? Thanks in advance,,,,Jerry

Please reference pins 87, 87a, 86, 85, 30. I have a standard 5 pin relay………. Thanks