Re: {FORGED?} Gas Gauge Question

[Tom Jennings <tomj@xxxxxxx>]

On Mon, 26 Sep 2005 AMC74Hornet@xxxxxxxxx wrote:

> Is their any way to check a gas gauge with a multimeter with the gauge out of the car with it not hooked up to the car? I have a spare Gremlin gauge cluster and if the gauge is no good in my Hornet I may be able to swap out the gauges. But I don't want to swap out anything unless I am sure.

Hmm... if you have the complete gauge cluster, or at least the PC
board and temp. gauge, yes.

THe temp gauge has the voltage regulator in it. It feeds the gas
gauge too. The gauges want less than 12 V. (It you look at the
third leg of the temp gauge with a volt meter you'll see it go ON
OFF ON OFF ON OFF ...  the average voltage is 5? 6? 7? volts. If
you look INSIDE the temp gauge you'll see the horrid little
bi-metallic strip and contact with the coil wrapped around it,
that's the regulator!)

Anyways, the TSM has the numbers, but the gas tank sender is close
to zero ohms when FULL. Therefore, with the gauges and PC board
connected to 12V right, grounding the sender wire to the gas gauge
should make it read full scal.


A really quick check would be, an ohm meter across the gas gauge
terminals.  If it's zero to 100 ohms it's almost certainly fine.
You should be able to move the needle, very carefully, and it
shouldn't bind, crunch, etc.  Don't push it far, just see if it
moves freely. If both these things are OK personally I'd stick it

in as good.