does anybody know if having a after market fuel pump will cause my fuel gauge to not work i got the wiring diagram and i tryed hooking staight up to the sending unit and my gauge still reads over full but does not peg the needle out cuase when you ground the gauge it pegs out to over full does anybody know anything about this setup its on a 85 k10 dual tank 4wd thanks

 

The new sending unit has to have the same resistance range as the original for it to work properly with the original gauge. It all works off of resistance. Zero ohms at empty and I believe it should be around 90 ohms when full, but I do not have time to look that up at the moment.

 

thanks for the info again i need to chech my gauge to see if its the right ohms.