fuel gauge problem 79

[shipy59]

Help, 79 owner with i think a sender problem! The gauge just decided to read off the scale to the full side,now it also reads empty at 1/4 on gauge.(thats when it ran out on me,doh) I found a loose conection at sender that fixed high peg situation but still reads high and varies a lot. Questions,does the tank need earthing or will the wire from sender to chassis be all for earth and will sender come out the hole above it or does tank need to be dropped out?????? Oh resistance on sender what to what ohms????? :confused2:

 

[mrvette]

The sender unit is variable resistor, and goes from Zero to 90 ohms but I forget which way is which...sorry...

sounds like the float needs bending a bit to make reading closer to reality...

:flash:

 

[Twin_Turbo]

0 empty, 90 full. Disconnect it and the gauge goes off scale, ground it and it's below E.

Sounds like either a sticking float, a kaput rheostat or some resistance in a connection somewhere, throwing off the scale.

 

[shipy59]

thanks for replys, looks like i will have to try and pull sender to check it. will sender fit out of rear deck hole??

 

[Twin_Turbo]

On a 79 yes after you remove the bib and the lid w/ base ring

 

[shipy59]

thanks will try it soon.

 

[shipy59]

Well guys pulled sender out to find it was very corroded.put an ohm meter on it and found high resistance at the terminal that wire goes on. So a bit of a clean with trusty dremel to make connection good with a dab of solder and i get a intermitent reading. pull unit apart to check windings and tighten spring inside unit. Much better,but on the high scale it still goes very high which i put down to worn windings increasing resistance. So other than a new sender its as good as it gets. thanks guys for your help.