Yes that is right. This lone wire from fuse link "R" (circuit 787) only has voltage (power) on it while the engine is cranking. This bypass power is to run the fuel pump(s) while the engine is cranking so the engine will start.
Circuit 787 bypass all other relays, switches and fuses and sends power right to the fuel pump. The fuel pump must run with power on this wire after the fuse link "R".

 

OK, so now I know what you meant when you said to put power to circuit 787. I will do so tomorrow. I already have the fuel line disconnected. If I don't see fuel, the pump is bad?

 

Maybe this will help:


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I'm quoting my above post to keep track of those sockets in the plug in the back. With 787 jumped directly to the positive post of the battery, but with the key in the off position this time, I got full battery power at the top socket. (Remember, I'm being forced to work with this plug with the "heart" in the upside down position, so the "top" is actually the bottom of the "heart".) I was also able to leave the 787 circuit hooked up to the battery for a long time (at least an hour) without anything frying. Nothing from the fuel pump. No noise, no fuel, nothing more than a little spark when I hook up 787 to the battery post.

So do we have positive proof that the fuel pump is toast? I just can't believe that. I've been working on cars and trucks since the late-70s and I have NEVER seen an electric fuel pump just quit. They always make a big production out of it first, with lot's of noise, whining, etc. I mean seriously, after all of this troubleshooting, it can't be just the fuel pump can it?

 

Yes I have seen a lot of them just quite.
But a lot of times the plug on top of the tank will loose continuity to the pump.

I may be wrong on yours but I think the plug looks like this:




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No, like I said, it looks round, but when you look inside it is actually heart shaped. It has three sockets. I think we have one for the fuel gauge, and one for the positive side of the pump, and one that may be a ground? I removed and replaced the plug several times the first time I was back there to clean up the connection, what should I do next?

I have a little room to work above the fuel tank. If I do need to replace the fuel pump, will the assembly come out the top without too much trouble or is it some long, giant contraption that has to pull straight up for two feet, requiring me to drop the tank? If that's the case this might have to get drug over to a storage yard and sit for another year cause this move needs to go forward!

 

I have not seen a three pin fuel tank plug and none of my diagrams show one. No auto part stores I bring up shows a replacement 3 pin plug pump either.

Yes you would need to drop the tank or cut a hole in the floor to remove the pump.

 

Is that where we are at now? The pump needs to be replaced?

 

You might try putting a fuel pump on the frame inline with the fuel line from the pump to see if you can drive it to the new location.
Note the fuel pump would need to put out between 7 & 12psi.

 

Yeah, I was already thinking that, especially since I apparently have some oddball set-up with a unique plug that I may not be able to find a replacement for. I forgot how Ford likes to change stuff every six months. It's one of the reasons why I've always had a love/hate relationship with Fords. One could say that it's because they're always improving things, while others will say it's because they didn't get it right the first time. Do I sound a little frustrated?

I'm just plain flat out of time. I have a lot of stuff and other cars/trucks that need to be moved too.

I don't know if it's going to be a week, a month, or a year before I get back to this, but I will report back when I have new news.

Thanks big time for all of your help!

Regards,
Eric

 

they are typically located behind the passenger kick panel. But on my F700, it is under the dash on the passenger side next to the center jump. It has a plunger on top that should be down. Use an ohm meter to check it. Should have connectivity with the plunger down and none with the plunger up.