Fuel gauge & fuel sending unit

[VitaminC914]

I recently had the tank removed to replace the lines. We did not remove the sending unit/float. After re-installing, the fuel gauge isn't working. If I touch the wire that is on the top of the sending unit to a ground, the gauge will read full. I wanted to replace the sending unit/float but the screws on it are so rusty, that I am not sure I will be able to budge them. I've soaked them with penetrating oil, etc, but no luck.
Is it possible that one of the wires going to the gauge is broken? If so, I would not get any activity on the gauge, correct?

Are there any electrical diagrams for the FJ60 on here? I keep hearing about the FSM but I have not been able to find a copy or link.

 

[g-man]

For Sale - 40, 50, 60, and 80 series FSM for a hell of a price.

download 1980 2f motor, 1981 2f emissions control, 1984 body - chassis, 1985 fj60 body and chassis supplimental, 1986 maintenance.

Look at the very back of the body and chassis, and body and chassis supplimental for wiring schematics.

 

[g-man]

My fuel gauge didn't work when I bought the truck. For years I would reset the odometer each time I fueled. Zero was full, 100 mi was 1/2 full and 200 was empty. finally I broke down and bought a fuel sender. I droppped the tank down, replaced the sender. Still the gauge didn't work at all. At that point I suspected the wiring. I found a corroded connection in the driver's quarter panel. It was down low in the quarter forward of the jack housing. The previous owner had water intrusion that got into that quarter.

 

[g-man]

If you grounded the wire on the sender and the gauge read full then your wiring between the gauge and sender is good. There should be two wires on the sender. Remove them and touch them together and see what the gauge does. If it doesn't peg full then it may be the other wire that goes to ground is not good, or most likely the ground connections is not good. Or you have bad contacts where the wires mount to the sender. In this image the wire going from the sender to the bottom of the page is the ground.

 

[VitaminC914]

If you grounded the wire on the sender and the gauge read full then your wiring between the gauge and sender is good. There should be two wires on the sender. Remove them and touch them together and see what the gauge does. If it doesn't peg full then it may be the other wire that goes to ground is not good, or most likely the ground connections is not good. Or you have bad contacts where the wires mount to the sender. In this image the wire going from the sender to the bottom of the page is the ground.

View attachment 1854938

Thank you @gman I will test it tomorrow. If that doesn't work, then I am guessing the sending unit failed.

 

[g-man]

I dont' know exactly where the ground wire connects to the frame but I just drilled a hole at the very back corner of my tank and ran a self tapping sheet metal screw up it to hold a new ground in place. I know you're thinking "a hole in the tank?" but you can where the top and bottom of the tank come together and flatten out. You may want to just clean some metal here with a grinder or scotch pad on a die grinder then clamp the wire on with vice grips and test it.

 

[ToyotaMatt]

I recently had the tank removed to replace the lines. We did not remove the sending unit/float. After re-installing, the fuel gauge isn't working. If I touch the wire that is on the top of the sending unit to a ground, the gauge will read full. I wanted to replace the sending unit/float but the screws on it are so rusty, that I am not sure I will be able to budge them. I've soaked them with penetrating oil, etc, but no luck.
Is it possible that one of the wires going to the gauge is broken? If so, I would not get any activity on the gauge, correct?

Are there any electrical diagrams for the FJ60 on here? I keep hearing about the FSM but I have not been able to find a copy or link.

since your fuel gauge in dash WAS working prior to the the suction tubes repair , Then after re-installing the tank , your fuel gauge stops

working , it would be Logical to conclude something was done or left Un-done that has caused the problem ..........



if i understand your description of events & timeline correctly ?


since u had someone else perform the repair , i would ask them why your gauge in dash is not working and see what they say


its common practice to drain a Toyota gas tank prior to removal , that's why theirs a service fitting on the bottom of the tank

maybe your tank is simply empty from being drained for the repair of the tubes



as far as your Rusty sender float Phillips head flange plate mounting screws , 1st go to your toyota dealer and order a Fresh New set & a

New rubber gasket too , Reusing any of that stuff is Not in any way a Option to consider





next wire brush the Rusty Phillips head screws Very Well , they need to be pretty much polished clean




next , use PB Blaster brand rust penetration solvent , this stuff works very well and quickly , most other stuff will not and wont


buy a Fresh new sharp set if Vise Grip Brand vise grips , harbor freight ones wont cut it here , and Vertically bite & lock onto the Phillips

head while pushing down hard , very hard . Very carefully & slowly rotate the Phillips head back and forth more and more , loosing at u go


repeat till u have all the screws out

 

[VitaminC914]

Thanks @RAGINGMATT I will try it again. My mechanic said he would be happy to look at it again when I get the truck out of storage in the spring. In the mean time, I can work on trying to get the rusty screws out. Should be fun.

 

[ToyotaMatt]

Its very straight forward & in the end easier rather then harder u will find out , if follow the steps to the letter

 

[VitaminC914]

Its very straight forward & in the end easier rather then harder u will find out , if follow the steps to the letter

I followed your instructions to the letter. I was able to get 4 out of the 5 screws. The 5th one had a broken head but I was still able to pull the sending unit out. Now, I will need to test it and see what is going on with it. I have a mechanic friend stopping by on Wed to help. Most likely we are going to install a new one. It is well worth it.