I have a 1975 K10 4x4. Everything works as it should. When I bought it the guy had took out the fuel guage because it did not work. So after many times running out of gas I finally decided to put it back in to see if what he told be was true. When I hooked it up the needle move to 3/4 of a tank. I thought it was working so I drove it through town to see if it would move as the gas was move around and drunk up by the built 350. Sadly it never moved. So I put a new guage in that needle didnt move at all. So is it the sending unit or have I wired incorrectly? It could be that there is more than on wire from the tank and Im not sure which is the correct one. And how many wires should come from the sending unit? Please help this important! :-(
try the ground wire on the sending unit . this will take two people one to watch the gauge and one to try the wire
GROUNDS clean them grease them make sure con. good YES the bigest trouble with sending unit is the ground after year "rust, winters, air, sand,"bad conection.
My unit has on two wires. One positive and one ground and my gauge only reads 1/4 tank. What should I do.
A Good Customer of mine (all he uses on his farm are Chevy trucks), Brought his '87 short bed to me with the same problem (Reads 1/4 tank all the time). After going through all the basics, and verifying no problem with the sending unit , or wiring, I suspected the gauge. 1947-1987 fuel gauges work basically the same: Low resistance= Low Gauge reading. High Resistance= Higher reading. @ Full the Sending unit read 150 Ohm, But it took 320 Ohm to make the Gauge read "Full". Gauge was replaced, correcting the problem. Also, Make Sure there are no "Mickey-Mouse" Splices in the Gauge wire, and that you have a good ground. Unless there is an in tank pump, there will be either one, or two wires.
