Gas Gauge

[matthon]

67 Barracuda, gas gauge does not work.
Questions:
How can I test the gauge and sending unit?
If both work, how can I bypass the existing wiring in order to wire it myself?
A new harness is out of the question at this point and playing the 'how much is in my tank' guessing game is eventually going to leave me on the side of the road.

 

[RedFish]

If the other 2 gauges work thats a good sign.
First look for the ground strap at the sender . It snaps on the metal fuel lines conducting ground over the rubber hose there. It may be missing.
Next attach the sender wire directly to ground and see if the gauge needle moves. It should peg full high as it can go. Dont leave this hooked up and hot for longer than 2 minutes or it may fry the gauge.
Let us know what you find .

 

[GermzD74]

67 Barracuda, gas gauge does not work.
Questions:
How can I test the gauge and sending unit?
If both work, how can I bypass the existing wiring in order to wire it myself?
A new harness is out of the question at this point and playing the 'how much is in my tank' guessing game is eventually going to leave me on the side of the road.

Saying it's only the gag gauge that's not working...

First I'd test the gauge and see if it's coming from the sender or its the faulty gauge. Disconnect the wire off the sender and once done the gauge should be at Empty still, then ground the wire to a nice clean grounded part of the car, and make sure its a nice clean part because I did it once and didn't work then tried a part where there wasn't much rust on just metal and it worked, the gauge should go all the way up passing Full.

If the gauge worked then there are great chances of having a bad sender, those are easy to take out and check. If it's the gauge that ain't working then you either have a problem with the gauge itself or the wire running up to the gauge may be cut by maybe a rat lol

But my guess is that if only your gas gauge ain't working but your temperature gauge is, then its probably not the voltage regulator on the back of the cluster and probably not your gauge as well, I place my bet on your sender. Hope this helps!

 

[GermzD74]

If the other 2 gauges work thats a good sign.
First look for the ground strap at the sender . It snaps on the metal fuel lines conducting ground over the rubber hose there. It may be missing.
Next attach the sender wire directly to ground and see if the gauge needle moves. It should peg full high as it can go. Dont leave this hooked up and hot for longer than 2 minutes or it may fry the gauge.
Let us know what you find .

You are too fast my friend! lol Excellent points I didn't know you could fry your gauge like that! And yep forgot about the strap on there, that should be also present and cleaned if it's rusted.

 

[matthon]

The other 2 gauges do not work.
There is no ground strap at the sender, (that's what those metal clips are on the lines!!).

The voltage regulator was attached to the gas gauge only, but is it linked to the other gauges by the electrical board?
I tried 2 different boards, one from another parts dash.

Since someone hacked up the harness I followed the wiring diagram and fixed some things, installed aftermarket temp, oil, and tach- but no gas gauge.

I will try to ground the sender wire and see if the gauge needle pegs full, but if it doesn't it is looking like the wiring is bad, (or more).

I am loosing my vision following the diagram, any idea how the wiring should be, including grounds, so I can at least install a gauge under the dash?

You guys are the best, thank you.

 

[RedFish]

The metal clips snapped onto the fuel lines is the ground strap. Now that we know all 3 stock gauges are dead we know the limiter in the fuel gauge is dead.
The voltage limiter that is normally found pluged into the back of most panels in inside the fuel gauge on rallye panels.
I'm guessing what you thought was the voltage regulator is actually the noise supression capasiter. Go here and read ... www.DeMonIVR.com

 

[matthon]

The metal clips snapped onto the fuel lines is the ground strap. Now that we know all 3 stock gauges are dead we know the limiter in the fuel gauge is dead.
The voltage limiter that is normally found pluged into the back of most panels in inside the fuel gauge on rallye panels.
I'm guessing what you thought was the voltage regulator is actually the noise supression capasiter. Go here and read ... www.DeMonIVR.com

I get it, I had no idea the voltage regulator was inside the fuel gauge, that explains why one of the gauges I have is burned out on the back.
To clarify, the metal clips are snapped on to the fuel lines, but that is it, there is no strap between them.
So, I need to get me a ground strap, a DeMonIVR, and go from there.
Looks like a nice piece, thanks again.