Should be a Flat Blue Rectangle rubber thing on the wire, I do not know what color the wire would be (maybe black). Yes it would have power at all times even with the key off.

Here is the inertia switch (fuel shut-off switch) location from the 1983 Owner Guide.

 

This is what I did/found last night. I made a fitting to put the oil pressure sender (bell shape) and the oil pressure switch onto. We got it all hooked up and started the truck. Fuel pump cut out after the truck started and it stalled out shortly after. We checked for current on the red/yellow hash wire right before it goes into the fuel shut off relay. We checked before we started the truck (no current) and we checked with truck running (current). So I know that the relay is getting current to run the pumps when the truck is started. Tell me if I am wrong but it now seems to be that the fuel cut off relay is bad. If this is my problem, is that relay the same one used for the fuel pump selector relay?

 

Looking at the diagram form the manual
http://i54.photobucket.com/albums/g91/subford/Fuel/837.gif
it seems to show that the Tank Selector Relay has two out put pins and the Fuel Pump Cutoff has one. But they still could be the same, you will just have to pull them out and look at them.

Jump your oil switch, turn on the key and see if you have Power (current) at the output wire from the Fuel Pump Cutoff Relay.
EDIT
If you do have power (current) at the output and the pump is not running then the Resistance wire may be bad.

I do not know why this Resistance Wire is there, maybe Franklin2 (Dave) can help us here. A guess would be that if the fuel pressure was up it might limit the current to the fuel pumps starting under load. But I would think that your vapor bypass would drop the fuel pressure real quick sending fuel back to the tank.

 

I found that relay at a local Ford dealership for $27.00. I am going to pick it up after work today and put it in. The old one is pretty corroded. It looks like water had gotten in there at some point.
If it is the resistance wire how difficult is that to replace? The female side of the connector would somehow have to come apart to connect the new resistance wire, right?

Eric

 

I do not know exactly what the resistance in the pump circuit is for. But if you were curious if it was bad or not, put your meter in rx1 scale, and make sure the needle reads zero when you touch the meter leads together. Then put one meter lead on the pink/black hash wire coming out of the fuel pump cutoff relay, and put the other meter lead on the pink/black wire going into the tank selector relay. If you get .75 ohms (pretty much close to zero) on the meter, then you know the resistor is good.

 

Well I have a new problem.
I installed the new fuel cut off relay. I started the truck. It ran for about 1 minute and cut out. When I got out and went towards the front of the truck I noticed smoke coming up from the fuel relays and near the starter relay on the passenger side. After investigating those areas these wires were burnt up: Black wire from fuel cut off relay to firewall ground ( burnt on relay end of wire) and the yellow wire with the blue fuse link that ties into the starter relay was burnt on the blue fuse link part only!?
Now I am really confused as to why that happened. Any ideas? Could it have anything to do with the resistor wire? After the truck (and I) cooled down, I took off the starter wire off its relay and turned the key to start. Both pumps run as they should still. I was worried that I burnt out the pumps.
I thought I was getting close to having this problem solved. I guess not.

My Fuel cut-off relay has these wires coming out of it:
Red
Yellow
resistance wire tied into pink/black hash
2- black wires

Your diagram only has 1-black wire coming out of the cut-off relay.
When the truck is running, what wire sends power from the cut-off relay to the pump relay?

 

As a guess I would say you installed a relay with the wrong pin arrangement. The one you put in had connection from the Yellow wire to the Black wire some where in the operation of the relay. NO The Black wires are grounds, no power is sent to any place except to ground over the black wires. They only ran one black wire to the relays from ground and then jumpered between them so when power was applied to the other side of the coil the relay the relay would change states. The Power from the cut-off relay to the pump relay is over the Pink wire with a Black Hash, the Resistance Wire may all so have this color code.

When you replace a relay you need to look on the side of the relay and make sure the diagram on the side of one matches the other relay.
If not you have to move wires around in the socket so it is electrically the same as the wiring diagram.

Also note that the wiring diagram above is an electrical diagram and not a drawing of how your system is laid out. I have not seen a system like this and all I have to go on is the diagram from the book, passed experience and what you tell me. Still no photos from you so I can not look at them and help you.

 

I am sorry about the picture's. My wife has the digital camera up at the lake. I will make work of getting those pictures.
I got the relay at the Ford dealership. The old relay has 4 posts and the new relay has 5 posts. The Ford people said that that relay is the replacement for the old 4 post relay. I assumed (my mistake) that all I had to do is plug it in. I will check that relay diagram to see what wires are different. I may just bypass that shut off relay all together. Too many darn relays! My truck is not an everyday driver.

 

If you get fed up, you could put a manual switch on it. If you go this route, this is what I would do first;

Go to the cut off relay and take the yellow wire and tie it directly to the pink/black hash resistance wire. The pumps should immediately run. Just touch them together and get ready to pull them apart if any smoke appears. We still do not know what the original problem was with this circuit, hence the reason the previous owner disconnected it.

If the pumps run fine for a few minutes with these two wires jumped together, then we can consider everything ok. Go get some 10 guage wire, and the heaviest automotive switch you can buy in the store(20-30 amp switch). Hook the 10 gauge wire you bought to the yellow, and run it to the new switch mounted under the dash. Come off the other side of the switch with another 10 gauge wire and run back out and hook it to the resistance pink/black hash wire.

Now everytime you go to start the truck, just flick the switch on, and the pumps should run.

Disadvantages to this way are; You have to remember to turn the switch on and off, and anybody else who drives the truck has to remember too. This could be a good anti-theft feature though.

You will lose your safety feature built into the system by Ford. If you use the yellow wire after the inertia switch, you will still have that feature, but you will not have the feature of the pumps cutting off if the engine quits. There are lots of street rods and dump trucks running around without this feature, and I have not seen anything on 60 minutes about it, so I think you will be ok.

 

I have another idea. Tell me if this would work. The oil pressure Switch that I bought has 3 posts. 1) ignition (hot in Run or Start 2) Starter (from starter relay) 3) From switch to the Fuel cut-off relay. What if I ran a wire from the starter relay post,where the pink/black hash wire connects, to the #2 post on the oil pressure switch (starter) and then tie in the red/yellow wire at the cut-off relay to the pink/black hash wire of the pump relay. In so doing bypass the cut off relay. The pumps would have power when in Start and then when the oil pressure gets up the pumps would have their power from the oil pressure switch. Assuming that that is how the oil pressure switch works would that work? I would at least have that safety if the oil pressure evr dropped.
Also, looking over that cut-off relay tonight it looks like one of those black wires was after market. The relay had 2 black wires 1 of which came out of the resistance wire hole. It looked like someone had enlarged that hole to get the black wire into it. That black wire was the one I had grounded to the firewall. Someone may have done that to rig the pumps somehow. Just a theory. I don't know if that would have anything to do with the wires burning up.

The other way I am going to have to 1st repair the yellow wire fusable link. Can I buy a fusable link anywhere?

 

You have lost me in what you want to do.
1. I do not know how this switch is made inside, everything would be a guess.
2. Yes you can get fuse link at any auto parts store, this one was 20 GA.
3. Why did you change the Relay?
4. Why did you not get the Oil Switch I found for you?
5. Do you understand the reason for having a Relay?
6. The Oil Pressure Switch you bough can not handle the load of the pumps, that is why the Relays.

 

The oil pressure switch will not pass enough current to the pumps. That is why the relay is there. The pumps draw a lot of current. That is why I said run the large 10 gauge wire and find the biggest switch you can in the 20-30 amp range.

You can buy fusible links at the auto parts stores. You need a fusible link or a fuse no matter what you do. You want it to pop before the wiring catches fire.

 

I think I fixed it. I replaced the fusable link on the yellow wire.
On the shut-off relay plug, I had the 2 black wires - 1 in the same hole as the resitor wire (burnt up). That one I cut off and caped with electrical tape. The other black on the shut-off relay was attached to the black wire on the pump relay. I spliced those to the ground going to the firewall. Just like the diagram that you gave me.
I started the truck and shut it off in about 30 seconds and checked for smoke/hot wires. Everything seemed good. I started it again and let it run for about 5 minutes (it did NOT shut off). While it was running I was checking for warm wires, Everything seemed good, no warm wires or smoke. The only thing I am concerned about now is if I got the right GA resistor wire. I will check around tomorrow for the 20 GA. I got the one that said Ford on it rated to work with 14GA. Auto Zone nor Advance Auto had a 20 GA.

 

I think I have this problem fixed. Thank you to Subford and Franklin2 for helping me get through this problem. I really appreciate all of you on these forums.

Thanks again.