wiring harness swap issues

[1lo620]

Ok I switched out a wire harness from a 76 620 to a 74 620, it was just a front part of the harness..Ok, the issue I am running into is the fuel tank gauge works, but I just realized that it is sending false reading. I ran out of gas and the gauge read 1/2 tank..So I got gas and filled it up about 1/2 way, now it is reading full. So is it the wiring or the float...everything seemed to hook up but not getting proper reading...'any info would help ..thx

[DanielC]

Most fuel gauges of around these years are just a variable resistor, in the tank, operated by a a float, and a meter that reads the difference in the position of the float, from full, to empty, or somewhere in between.

 

Changing the wires that connects the gauge, and the sender should not affect the way the gauge works. I would check the connections between the two, and do not ignore the ground. The ground may or may not use the bed, the frame, or even the cab as part of the circuit.

[Eagle_Adam]

did the gas gauge function properly before the swap?

[1lo620]

this is a rebuild so to speak,,,the truck has been sitting since the mid 80s. and it had a complete custom interior. All after market gauges,, everything had been switched to toggles,,,SO I gutted it and started over, put in a different dash that I had..and wire harness...so I dont know if it worked or not...Just need to figure out how to get it to work. I have several after market fuel gauges that can wire up,,,or can I replace the sending unit in that tank?

[Eagle_Adam]

not cheap at all but here is an option

 

DATSUN 620 FUEL TANK SENDING UNIT

 

FITS SHORT CAB

 

PART: PL62022 $113.00 US. *

 

 

 

 

at http://www.new-datsun-parts.com/datsun-pl620-truck-parts.html