Author Topic: Fuel gauge and voltage regulator  (Read 6508 times)


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  • Posts: 1
  • Gender: Male
  • Mustang: 1967 Coupe
  • Location: Bournemouth, UK
Fuel gauge and voltage regulator
« on: August 19, 2012, 09:04:22 AM »
This is my first post here, so before I bore everyone with the irritating problem with the fuel gauge, I think it's best I introduce myself....
I had my first project mustang (67 Coupe) shipped to the UK in January and have been working away on getting on the road here since then! Most things have been simple fixes, but their are a few issues driving me crazy   :o
Im hoping to use the Mustang for my wedding in November and then turn it into a road legal track car (part of the wedding deal!).

The problem I'm currently stuck with is the fuel gauge. I've read so many threads but can't find an exact answer that seems spot on.
The fuel tank looks fairly new, as does the sender and wiring etc...but the gauge is the original in the cluster. The fuel gauge contiguously reads empty. The sender is grunded and works, so I'm putting the issue down to a problem with the gauge/voltage regulator behind the cluster.

I'm finding it quite difficult to pick up a voltage regulator here in the UK, so I have ordered a simple 1.5A (5/6V) regulator to try and replace the original with. If this does not work, has anyone on here every wired in an aftermarket 12V fuel gauge and simply by-passed the voltage regulator?

Any suggestions would be greatly appreciated!!



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Re: Fuel gauge and voltage regulator
« Reply #1 on: August 19, 2012, 10:03:33 AM »

The fuel gauge, oil pressure gauge and temperature gauge are all the same - the only difference is the face.  So if your temperature and oil pressure gauges are working then the voltage regulator is working too (assuming they are the stock units in the dash).

A very common cause of the fuel gauge reading empty is a leaking float inside the tank on the sender - it fills with fuel and will no longer float, leaving your gauge always reading empty.  The easiest way to check the gauge is to turn the key to "run" and briefly ground the wire that attaches to the sender from the gauge.  If the gauge moves toward "full" then the gauge, wiring and gauge voltage regulator are OK and the problem is with the sender.  But don't leave the ground in place for very long because it will toast the gauge after a time.

If the gauge does not move and your other gauges are working, then I would look for a bad connection between the gauge and the sender in the wiring somewhere.  You can start from either end but the traditional troubleshooting usually tries to divide the trouble area in half at each step so if you start at the sender, you can check the continuity between the sender connector and the wire in the door channel to see if it's good.  If so, continue towards the dash ...

Give that a shot and let us know what happens.
Also, to more directly answer your questsion about the regulator, there are others out there that have done this.  There's a pretty good tutorial for doing that here:



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