67-72 Chevy Truck fuel gauge diagnostics 101

[bamabronc]

Hey guys, I’m stumped with my fuel gauge. Here’s my story. The fuel gauge never really worked since I got my 72 so I decided to change the sender. After install it stayed at 1/4 tank. After searching here I determined it had to be the resistor, so I checked the ohms on the resistor and nothing. Ok, so now I order a resistor and new printed circuit from truck shop. I then installed the new printed circuit and the resistor. It read 3/4 tank so I drove to fill up and it stayed at 3/4. So I take the cluster out again and thought well maybe I put the resistor on wrong because I had the circuit under it. I changed it so the circuit is on top of the resistor. Now it reads 1/4 again, but I get 86 ohms on the resistor, so it should be good. The gauge ohms are very similar to the ones in this thread and I get 90 ohms on the #4 wire and 14v on the #3 wire (on the tender). I have already verified that the sender ohms moves from 0 empty to 90 full. Also, the gauge test with the wire off the sender goes to around 2 o’clock and grounded goes to empty. Is the copper on the resistor supposed to touch the copper on the circuit? Any ideas as to what may be my problem? Your help would be greatly appreciated. Thanks.