The below response is from Bill Hanlon a while back when, I beleive Smokey
was having problems with his guage--Note that the biggest majority of gas
guage problems is a bad ground....Wayne
Good info below...
You can't use the volt/ohm meter to verify the gauge, but you can use
it to verify the sending unit.
1. Disconnect the wire from the terminal on the tank's sending unit.
2. Connect the meter between the terminal on the tank's sending
unit and a GOOD ground (clean with a little sandpaper) on the tank.
3. Set the meter to a low ohms scale. The TF trucks read around 30
ohms when "full" and near zero ohms empty. If the reading is wrong
fix or replace the sending unit. In mine, the brass strap that
connected the actual variable resistor at the bottom of the sending
unit to the terminal on the outside of the sending unit was broken
and was easily repaired with 100 watt soldering gun.
If step 3 checks out good, you can figure out where the wiring is going
wrong by making a test rig that consists of a length of 18 gauge wire
attached to an alligator clip on one side of a 15 ohm resistor with
another length of wire attached to a sharp pointed device (I used a
large paper clip and ground a point on it). Exactly 15 ohms is not
important, 10 to 20 will do.
4. Disconnect the gas gauge wire where it attaches to the tank.
5. Hook the alligator clip to a good ground in the truck.
6. Turn on the key, but you shouldn't have to start the engine.
7. Touch the pointed end of the test rig to the gas gauge terminal
that goes to the gas tank. If the gauge reads still reads
full, the problem is in the gauge, the grounding of the gauge
or the power circuit supplying the gauge. If the gauge reads
around half full (or half empty if you are a pessimist) continue
probing the gas gauge wire as it makes it's way towards the tank.
When you reach a point that the gauge no longer reads half full
as you probe the wire you have gone past the open (break) in
At 04:31 PM 11/4/99 EST, you wrote:
>Can anyone advise as to where to start in determining whats wrong with my
>gas gauge? It may be the unit in the tank. Where do I start? Will replacing
>the unit in the tank take care of the problem? This 54 3100 has been
>converted to 12 volt. Would this have anything to do with it?
>Be pleased to hear from anyone that has restored a 54. Just go tmiine and I
>need to do some work on it to get the way I want it.
>oletrucks is devoted to Chevy and GM trucks built between 1941 and 1959
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