fuel guage reading funny?
 

i installed a 4o gal tank in the rear of my truck today and when i hook up the sending unit wire it reads half full , but it was bone dry so i put 5 gal in it and it reads 1/4 past full. is it a bad sending unit or are thay not compatiable with are trucks guages? my truck is a 71 and the tank is out of a 84 blazer. any help please!

Re: fuel guage reading funny?
 

The sending unit on our year trucks sends a signal to the dash unit from 0 ohms to 90 ohms, (0=empty, 90 = full). I would suggest checking your sending unit to see what ohm range it is has. You may have a bad unit or the ground could be acting up. I don't know what ohm readings the 84 is supposed to have.

Jim