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Hello guys and gals! I have a question concerning my 1990 F 150 truck.
Seems my temp gauge and one of my fuel tank gauges have decided not to work. If I switch to the front tank I don`t have any movement in the gauge,but the fuel pump is still working,If I switch to the rear tank the gauge works! as does the fuel pump for that tank.
I tried replacing the temp. sensor but that didn`t help with the temp. gauge. Iv`e checked the obivious >fuses and looked for bad connections . I do have a wiring diag. but so far Iv`e had no luck in finding my problem.
Any help would be appreciated TIA
Find the correct sensor for the temp guage on the engine. Remember there is probably two temp sensors on the engine. One for the computer(fuel injection), one for the guage. Look at your diagram, find the correct color wire, and pick the sensor that goes to the gauge. With the key on, pull the wire off the sensor. The temp gauge should swing full scale one direction. Then take the sensor wire, and touch it to ground. The temp guage should swing all the way the other direction. If this works, your gauge and wiring is good, and you have a bad temp sensor.
With your fuel guage you can do the same test. Switch to the front tank. Take the wire off the front tank sending unit, and let it hang in the air. The fuel guage should swing one direction. Then ground the sending unit wire, and it should swing the other way. If this works, then your sending unit in the front tank is bad.
Thanks Franklin 2 !! i HAVE REPLACED THE TEMP SENSOR AND MY GAUGE IS WORKING NOW!! I replaced the oil sending unit and now have a good reading on the oil pressure. I`ll try the trick for the gas gauge and see if that works.
Seems starnge all these things going bad at one time?
I did have to replaaace the battery also when all this started.?
Never have had any problemss with this ole truck untill this.