Fuel gauge wiring 1940 Hudson

My basket case came with a restored tank and an new sending unit. I will not be using original wiring harness and will be going 12v after market cheap hot rod wiring kit so will use a voltage reducer for original
gauge. Bottom terminal had one wire top terminal had 3 wires going to it. Is there a simple way to explain how fuel gauge system should be wired?


  • charles4dcharles4d Posts: 564Expert Adviser
    edited January 2019
    I think the 3 wire carry electric  to other  gauges so it would be easier  to wire the system you need a wiring  diagram to see how the old system works to understand  how it works good luck  I m still working  on my 1940 wiring my self if I can help let me know my system is a 6 volt
  • 29sptphaeton29sptphaeton Posts: 294Member
    You will need a runtz for your 6 volt gauge to work with 12 volts. It attaches between the incoming live wire and the gauge. They’re available from Speedway Auto. You need one for each gauge with the aftermarket harness instead of feeding from one gauge. For the lights you just replace the bulbs with 12 volt bulbs
  • Thank you both!! Just what I needed to know!!
  • PAULARGETYPEPAULARGETYPE Posts: 1,755Senior Contributor
Sign In or Register to comment.