Fuel Tank Ground
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From: Suffolk, VA USA
Fuel Tank Ground
I'll try this one on here too...not having much luck in 80-86 forum....
Does anyone know where the fuel tanks actually physically ground? My 86 has a single tank, and the black wire off the sending unit disappears into the harness. It doesn't seem to ground anywhere near the tank. I can't tell where it goes short of taking the harness apart to trace it. Not being a fan of unecessary work, I'm hoping someone on here knows.
Thanks,
Does anyone know where the fuel tanks actually physically ground? My 86 has a single tank, and the black wire off the sending unit disappears into the harness. It doesn't seem to ground anywhere near the tank. I can't tell where it goes short of taking the harness apart to trace it. Not being a fan of unecessary work, I'm hoping someone on here knows.
Thanks,
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From: Suffolk, VA USA
Thanks Bill...this confirms what I thought....I've got that big ground just to the right of the radio. There's a mass splice in the harness about a foot from that ground point where about 10 grounds splice into one large wire to the ground point. I suspected the tank ground was one of those wires. I had the dash open this weekend and that connection was solid with no signs of corrosion.
I'm trying to figure out a balky fuel gauge...it works, and has full range of motion in the needle, but drops way too fast...reads empty when there's still about five gallons in the tank. I've replaced the gauge, instrument voltage regulator, and sending unit (including a new float) for various other reasons, and thoroughly cleaned the wire connections at the tank and the under the brake booster. I guess I'll go back to the connections.
I'm trying to figure out a balky fuel gauge...it works, and has full range of motion in the needle, but drops way too fast...reads empty when there's still about five gallons in the tank. I've replaced the gauge, instrument voltage regulator, and sending unit (including a new float) for various other reasons, and thoroughly cleaned the wire connections at the tank and the under the brake booster. I guess I'll go back to the connections.
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From: Virginia
Doesn't your guage read about 90 ohms empty and 0 ohms full? What I would do is pull the sending unit again, hook the wiring up, turn the key on, and experiment with the float positions. The float should run out of travel and stop, and still be above the suction tube sock for the fuel. This is when the guage quits reading, and should leave about 2 or 3 gallons in the tank. From your description, it sounds like the guage is on empty way before it hits the stop. If you find this to be true, then you can bend the float arm a little bit to move the reading one way or the other.
Don't get hung up too much on trying to get the system to read really accurate. It just gives an average reading anyway, since the fuel sloshes around in there pretty bad when driving. I personally would not worry about leaving 5 gallons in the tank, so long as it's consistent.
Don't get hung up too much on trying to get the system to read really accurate. It just gives an average reading anyway, since the fuel sloshes around in there pretty bad when driving. I personally would not worry about leaving 5 gallons in the tank, so long as it's consistent.
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From: Easton,Ks
Originally Posted by Mil1ion
Judging from the schematic it looks like it grounds immediately after it leaves the sending unit.
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Dave...I hadn't thought about approaching it that way, but it makes perfect sense...looks like I have my weekend project.
Thanks,
Bill
Thanks,
Bill
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From: Easton,Ks
Originally Posted by ri_truck_guy
I'm trying to figure out a balky fuel gauge...it works, and has full range of motion in the needle, but drops way too fast...reads empty when there's still about five gallons in the tank. I've replaced the gauge, instrument voltage regulator, and sending unit (including a new float) for various other reasons, and thoroughly cleaned the wire connections at the tank and the under the brake booster. I guess I'll go back to the connections.
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The fuel gauge reading in the rear tank on my '90 behaves like yours. It is a recent development, and since everything else works normally, and the front tank reads properly, I was thinking ground as well. I may try a ground strap of some kind just as an experiment. Better to read lower than it really is than the other way around!
A related question. Do you guys ever run a tank completely empty? Like on a long highway trip or something. I have never done this thinking it would not be good for the fuel pump.
A related question. Do you guys ever run a tank completely empty? Like on a long highway trip or something. I have never done this thinking it would not be good for the fuel pump.
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From: Suffolk, VA USA
I haven't done it yet, but I've thought about throwing a gas can in the back and driving around until the tank ran dry just to see what happened with the fuel gauge. I don't know how far the gauge will drop when I run out.
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Originally Posted by subford
All ford trucks at least after 1980 all have their grounds for the gauge sender and electric pumps if they have them either in the cab or on the radiator support.
I looked it up on my Parts illustrations CD's and it showed the harness without a ground wire near the SU
