Yes it is.

 

OK now ground pin #6 of the self-test plug and turn the key to the run position.
Does the selected fuel pump run?
If not do you have power on the dark green with a yellow stripe wire at the fuel pump socket?

The self-test plug is called just EEC in the below diagram.
Attachment 280131

Attachment 277922

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Sorry, I didn't see the second response until just now. I ground out #6 like you show here and turned the key. I don't think I hear anything back there. I hear a couple other things powering up but don't hear anything when I open the fill cap and listen when someone turns the key for me. I disconnected the fuel pump relay like you have shown but I don't see a brown wire on it. I see Red, Yellow, Green/Orange and Green/yellow. Did I misunderstand where the brown is? I don't see a brown on the brown base EEC connector either.

 

The 1990 EVTM calls it brown but I guess the EVTM is wrong again.
After looking it up in the big 1990 foldout it says it is a dark green wire with a yellow stripe.

 

Oh, OK. I am seeing a few different wire colors on the diagram that don't quite match up. But, with #6 jumpered and the key on, there is power on green/yellow. Only when plugged back in.

 

What do you mean "Only when plugged back in "?

 

I had unplugged the connection at the fuel pump relay when I was looking closer at the wire colors. If I have that unplugged, no power at green/yellow. When I plugged it back in and tested it again, there was power.

 

That is because the green/yellow wire gets its power from the fuel pump relay.
Now you need to check to see if you have power at the inertia switch with pin #6 still grounded and the key in the run position.
Power on both in and out wires.

Maybe this will help:


Attachment 281923

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Yes, there is power on the green/yellow when jumpered and key on. I tested red/yellow while I was in there and it also has power.

 

Then you either have a bad selector switch at the dash or bad wiring to the tanks or bad fuel pump or a bad ground for the fuel pumps.

Attachment 285111

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OK. So here is a backside picture of my selector switch. If I have the key on, these should have power when #6 is jumpered for each tank, right?

 

Yes for the selected tank.

 

OK. It looks like the switch is fine. It ended up being the other red one behind the one I pointed out for front. When I select front, the test light turns off/on when I switch between tanks and same with the brown/white. So, it sounds like I have some crawling around to do under there looking for the wiring and determining if it's both pumps or ground or bad wiring. Are these grounds in a common place I can find easily? Does it indicate anything that the fuel gauge is goes past full when I turn on the key?

 

The pump and gauge ground G100 is located at the LH (drivers side) of the radiator support.

That would be a high resistance to ground or and open ground.



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Well, I can see the black ground that apparently goes to the orange wires to each pump. It's all wrapped up tightly in a bundle so I guess I'll need to open those up and see if those are intact. Would it be smarter to first try to run direct power to the pumps and see if they run and rule out dead pumps? If so, do you know if there is an inline connection somewhere I can reach without dropping the tanks to do that?