Fuel gauge?

Sounds to me like a failed sender.

Not helpful Tom...

That's like saying it's dark at night because the sun isn't out!

 

It's obvious the 'sender' isn't sending.

I want to know why and how to fix it

 

Is the problem analogous to a flashlight battery that wears out and has to be replaced...or is it a non apparent corrosive contact that can be repaired?

Could also be a short or a loose wire.

Ed...Uncomplicated simple wiring and nothing has changed. Nothing is loose. ground is good

 

Well you started talking about the gauge.....Most of these cars have cheap, simple float, variable resistance sender.  Replacing it probably the most reasonable.  However, it could be just a loose wire.  Start by checking the connections @ both ends.

Carl, open the front trunk/bonnet/whatever you want to call it. Disconnect the wire to the sender. Turn the key on and observe fuel gauge, it should read either full or empty. Now ground the sender wire to the chassis, it should read either empty or full(opposite of the open reading). If you find exactly what I described, buy a new sender, yours is busted. If you don't get the full and empty readings, the problem is your ground to the gauge or sender, or the wiring to your gauge.

 

Senders seem to run 25-30 bucks..

Hallalula!!...Thank you Danny

Carl:  In addition to Danny's comments (yes, Matilda....I'm a little late to the rodeo, here) all the sender is, is a potentiometer made of exposed, resistance wire wrapped around a curved carrier which then has a wiper riding across the exposed, resistance wire.  Over the eons it has probably been around, the wiper wears through the wires somewhere and opens the circuit so it no longer "sees" ground - hence, reading full all the time.

 

Also, note the direction in the tank that the float lever on the old sender is oriented when you remove it - That's important, as they tend to fit in one or two directions as defined by the mounting studs (I believe the studs are "keyed" by position). 

 

When you replace it, try to get one that's close to the same look (and/or part number) as what you have now, then bend the float arm about the same (you'll find that the arm on the new one is probably bent quite a bit different than what you have).  That'll get you in the ball park for registering contents right.  

 

To get it to read the level correctly (the shape of the tank is actually kind-of irrelevent), will take a little trial and error, but your old sender float arm does not have the correct bend angle.  

 

There should be an acute bend closer to the sender module, and a gentler angle farther out on the lever - You need to open up the angle closer to the sender a bit.  Just hooking the sender up to the gauge and moving it through it's motion won't work - you have to adjust it to your tank, and to do that you have to see where it sits when the tank is "full".  If it takes a long time to get off of "Full" and then drops like a stone you need to open up the arm angle to compensate. This might take a few tries.  I use a dip-stick into the tank to decide how full it is to help set the arm angle if the tank isn't full when I'm playing with it.

 

gn

What about using the costlier 914/late Ghia (T3 too) "column-looking" sender?  Is it the same resistant based technology?  It does cause a guage to giggle when driving or nee the vibrator to smooth out the giggles.  T1 sender is now $20 at CIP1 and the T3 is $50. 

 

I have read article (SAMBA?) about repairing the T1 sender - involved rewinding the coil.  Not sure if its worth effort for $20.  Be sure to order new sealing gasket.

 

My old '57 VW had a wood ruler vs a gauge.  Remember driving couple weeks and pulling into gas station to fill up - "that will be 39 cents kid."  Thank goodness it had a foot operated reserve switch --- I couldn't afford 40 cent fill up every 2 weeks!

I thought of recommending the later Ghia, tube-type sender, but thought that under the circumstances, going with what he already has is the best bet.  I believe the tube-style doesn't have that "floating needle" effect we all see - except for Wild Bill  - but I'm not sure it fits all tank configurations, that's all.

 

Carl:  You might be able to find one locally.  Looks like Axel's Foreign Auto Parts has at least figured out how to load up the first four pages of Google hits with their link pointers, but Napa or CarQuest might be able to get one in a day or so, too, unless you head online..

Bug City on the outskirts of Hartford is great too, very convenient for Lenny, maybe Carl too?