2000 fuel pump circuit opening relay wiring

Need help trouble shooting this truck I bought that doesn’t start.
Here’s how it’s gone so far, the truck had no power at all with key on and fresh battery.
- Replaced the main power to the fuse block it was badly corroded
Cleaned and greased connections to alternator
Added ground from battery to body as it was missing.

- tried turning it on after that and still no juice

- checked alt 80a fuse and it was blown folded the prongs back over so they’d touch since I didn’t have one on hand.
-
turned the truck on and cranked it over no start.

- checked blue wire at fuel pump and not getting power when cranking.

- went back to the circuit opening relay and probed the wires. There’s power going in to the relay at pin 3 when cranking but nothing coming out when in on position or when cranking, you can hear the relay click when cranking.
Not sure how accurate it is but a video online said that pin 2 should be powered when the key is in the on position.
And please forgive me on my probing method couldn’t think of a better method at the time.
I jumped pin 3 to 1 and got power back at the pump when cranking obviously but not sure if that’s the correct sequence by which it powers the pump.


would the efi relay being bad effect the circuit opening relay getting power?
Is the red and white wire actually the supply for that relay becasue backed of a diagram it traces back to the ecm

any help is appreciated.

 

The red/wht wire gets its power from the PCM the the PCM gets it power from other relays/fuse(s). If it was me I would unplug the COR(circuit opening relay) and with a suitable jumper provide +12v to the blue wire and listen for the pump, if it works, crank her over and see if she starts.

You have created a time bomb for yourself by piercing the wires the way you did. Corrosion will set in and you will have this problem again. They make liquid electrical tape... a few dabs and you are good to go.

 

Yes I know but at least I know where it is besides like you said, I just ordered some of that stuff about ten minutes ago haha.
And yes I jumped pin 1 and 3 because 3 is what was getting power on cranking. And it got power at the pump via the blue wire. Unsure if the pump is actually good. But either way I’m not getting power under any condition at pin 2/ the white and red wire

 

Its a twin coil......when cranking pin 1 is power just to the coil.....and pin 4 gives that a ground

pin 1 only has power at crank position


When you release the key from crank to on position.....now pin2(white/red) takes over and powers that coil....
and then the ecm uses that bright green wire from the ecm as a ground now to close that relay and send power from the white/red to the blue 12v pump wire


when in on position .....if the ecm sees no crank signal.........it will not provide that ground
therefore open/relay springs back open as soon as you release crank pos...or engine stops turning



pin 2......wire/red should always be 12v ....both in crank and on
however ,its the ground by the ecm that controls whether blue output wire is on or off when in run position


So .....just hearing a click....may mean only 1 side of the coil is working

there's dielectric fluid in the coil......it eventually leaks out and fails.....can gum up the connector below it


IF you crash out and there is no crank sensor......you dont want to burn to death ...do you

 

Thanks everyone o was able to get it going, when I first started tinkering with it I checked the efi fuse and could have sworn it was ok but today when checking the relay pins there was no power, checked the fuse and it was blown. Replaced it and it fired right up. Has 365k on the dash and I’m pretty sure the transmission is done for

 

Manual or automatic?