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The fuel gauge on my '48 Chevy 1/2 ton p.u. does not work. On the backside of the gauge cluster the "cardboard? bridge" between the two posts is missing. Is this a critical thing to have in place? Wht purpose did it serve? Please advise. Thanks.

It is an electrical insulator to keep the two wires from grounding to the gauge housing. You could make an insulator out of a piece of plastic (like a milk jug).

LMC truck sells a kit for that

Item 36-1238

http://www.lmctruck.com/icatalog/ca/full.aspx?Page=30

page 30 item 2

Good luck

Part # 36-2138

Thanks for the info. All other things aside, could this explain why the fuel gauge will not register? I realize that I perhaps have other trouble-shooting to think into.

It is possible, if the sender side of the guage is grounded, it will read empty all the time. You can do this quick test to help isolate the problem. Disconnect the sender wire at the tank, if the guage now swings to full, guage is good, trouble is in the sender itself. While you're looking at the tank, make sure the sender wire is actually hooked to the sender terminal at the tank, and not the ground terminal.

If disconnecting the sender wire at the tank has no effect on the guage, make sure the sender post on the guage isn't grounded or that the sender wire itself isn't pinched under something and grounded, and make sure "hot" side of the guage is actually getting voltage when you turn the key on (you can check this with a trouble light or a voltmeter).

Thanks for the correction
Gauge pic

Did the Gauge ever work?
Have you converted to 12Volt?
Is it the original sending unit?

My truck was converted to 12 volt, sending unit was froze in one position, and the gauge was 6 volt. Had to repair all of that.

Just things to look at
Good luck

Fuel gauge has not worked since I purchased the truck Spring 2009. All other gauges in cluster work. It is still 6V. Sending unit was replaced prior to my purchase. Float in sending unit was pulled and it does float as designed. Wiring has been examined and is correct and does not appear to be an issue. I AM BANKING ON THE LACK OF INSULATOR CITED EARLIER AND WILL ORDER KIT FROM L.M.C. IN THE A.M. Will attempt the other trouble-shooting at gauge posts as suggested if that does not do the trick. Could gauge cluster/chrome bezel and contact in dash panel be an issue of concern?

Also, please refresh my memory on correct wiring to the fuel gauge...when viewed from the back of the cluster (as in photo posted earlier), the upper left post goes to the ignition--correct? Likewise, the lower right post goes to the sending unit--correct? Please confirm. Thanks.

Logic tells us that if you are empty, you need more juice, so power in goes to the empty side of the gauge. You want your tank to be full so wire the tank to the full side. This has worked on any gauge I have dealt with.

So do I have this wiring reversed? Please clarify. What happens if this is powered up with wires reversed?

It will either fry the gauge or make it read empty all the time.

Any idea what might be happening if my gauge reads Full all of the time when ignition key is on? I am thinking the float might be stuck, but it would be great to get other ideas before I drain the tank, etc.

The lead between the gauge and the sender might be disconnected or broken.