yellowallison

I have done all the Fuel Pump test and determined that my fuel pump is working ..........to the point i now have jumper wire going from the battery to test connection (B) which has the fuel pump working and truck running fine.!!

Orginal problem is Truck will not start via keyswitch.....

I imagine my CO relay is bad!!!!!!

My Question now is this????? what would be causing me to not have Power at the Fp test connection????? the reason i have jumper going from battery to B connection is during testing I determind i have no power at the FB connection??

Could not having power at Fp test connection be related to my orginal problem??

Any help would be VERY MUCH APPRECIATED or links to more info and hope I making sense with my question aka troubleshooting !!

Been really nice to use this board to trouble shoot all that I already have...just now trying to figure why I dont have power at the Fp connection so I can continue troubleshooting?

IS it possible my main relay is Bad???????????

Thanks.

scope103

It's probably not your circuit opening relay, it's probably somewhere in the direction of your EFI Main Relay. The power to the B+ connector on the diagnostic port is from the EFI Main relay. If you don't have B+ then nothing else in the engine electronics will work.

So how could your truck run "fine?" The jumper to the FP connector may be supplying power back through the CO relay to the EFI bus.

Of course, it might not be the relay itself; you could have a bad ignition switch (which powers the EFI Main relay). Nothing beats being systematic. Follow the stickys to a service manual, be sure you have a cheap-ass voltmeter, and follow the electrons.

PS: get rid of that jumper to FP. If you have an accident some day, that jumper will make sure the Fuel Pump is running even though the engine is stopped.