72 chevy fuel gauge problem
 

I have a 72 chevy k20 4x4.
The fuel gauge stopped working one day so I replaced the sending unit, that did not fix the problem so I replaced the fuel gauge itself, still not working, I replaced these with new ones from LMC truck.
Any suggestions. Thanks for your help
Larry

Re: 72 chevy fuel gauge problem
 

It kind of depends on what you mean by not working... The needle doesn't move at all, or it fluctuates, or goes over past full. Stock tank? More info would help a lot. The wires are known to short out under the drivers side door sill or come unplugged from the fuse box or maybe a blown fuse. You will be looking for a 16ga brown wire... let us know.

LockDoc

Re: 72 chevy fuel gauge problem
 

Quick questions:
Do you have dual fuel tanks?
Do you have a electric/toggle switch for them under/around the dash?
If so, try the switch in the other position.
(noting that it is a K20...3/4 ton)
Coley

Re: 72 chevy fuel gauge problem
 

Only one tank and it is stock,the gauge is pointing about at the 9:00 postion and then goes up to empty when the key is turned on and the tank is full. I will check for a short under the door sill tomorrow. The old gauge would go to full when I unplug the brown wire from the sending unit I have not tried that on this gauge yet.
Thanks for your help..

Re: 72 chevy fuel gauge problem
 

If you touch the sending unit wire to ground, the gauge will go to EMPTY. If it doesn't do that, the problem is somewhere before the sending unit. There's lots of posts on this if you search fuel gauge or something like that. If you take the sending unit out, you can check the resistance of it with a multimeter. They are usually 0-90 OHMs. As you move the float, check to see if the resistance is changing.

Re: 72 chevy fuel gauge problem
 

thanks for the suggestion I will check it out