Question For JD 4230 Owners

[JD5210]

I am helping my neighbors dad with repairs on his 1977 JD 4230 cab diesel tractor. What is next on the list is the fuel gauge. The gauge is always on full, when the key is in run position. When I disconnect the wire at the sender and ground it on the tractor, the gauge goes to empty. To me this is backward how things should work. My question is this normal?

I have taken out the gauge out of the cluster and the gauge by itself works this way. I have not taken the sender out as the tank is full.

Thanks in advance for any help on this.

[jd110]

That is normal reaction of the gauge. Most likely you have a bad sending unit. Occasionally, the gauge can still be bad when it reacts normally when grounding the sender wire. The oonly way to know for sure is by connecting a known good sender.

[cowski]

i had that problem in a 4630.it was a short in the sending unit.

[kentuckydiesel]

I've only had this happen once on a JD 2640...bad sending unit.

-Phillip