Allen - If the connections are all good, as you say, the real problem
is your sending unit. Inside the sending unit there is a resistance
strip made up of resistive nickel wire wound around a bakelite strip.
A wiper contact rubs against this resistive strip. As the tank float
rises or falls with the gas level, the wiper's position against this
strip changes and the sending unit's resistance changes. The gas
gauge is actually a simple resistance meter which measures current
flowing thru the sending unit to ground. Thus the meter shows how
high the tank level is.
You can take the sending unit apart by removing it from the tank and
drilling out the rivets. If you're lucky, the resistance strip is not
broken and only needs to be gently cleaned with rubbing alcohol or
electrical contact cleaner (from Radio Shack). You should also gently
clean the contact wiper with a point file. Don't bend it so it no
longer makes proper contact with the strip.
You can measure the resistance of the sending unit with an ohmmeter
(also from Radio Shack). It should range smoothly from 0 to around 30
ohms. If you can't come up with the necessary repairs to obtain these
readings, you can buy a new sending unit from the catalog houses.
Good luck.......jay
On 9/16/99, Allen Coblentz wrote:
>I have a '52 Chevy truck........converted to 12 volt. My gas guage
>needle jumps around alot. I have installed a voltage reducer/resistor
>and switched the polarity around, as required. Every once in a while
>the needle seems to settle down and read correctly for a second or
>two........then back to jumping again. This seemed to suggest a loose
>wire, but I have checked them all and made sure the ground was good.
>Anybody got suggestions for my problem? Thanks, Allen
Jay Duncanson jay@duncanson.com
oletrucks is devoted to Chevy and GM trucks built between 1941 and 1959
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