need help wiring gauge for lpg

[howsie]

Cruiser has s 0-90 ohm sender on tank so I brought a analogue 0-90 gauge for it as the other gauge stopped working. Problem is its an autometer gauge and the wiring diagram supplied isn't real helpful. One wire is ground that's easy enough but where do the two from the actual sender go to.

[DamTriton]

To the other connection???

Not trying to be silly but a bit more information about how many wires come out the back of the gauge, what colours they are, and what the back panel of the gauge is stamped with(letters symbols) etc may help us give you a better idea of what to do. Scan and post up a copy of the information you have.

We're not there. YOU are our eyes.

[howsie]

Gauge on the tank has two unmarked prong on it I am running new wires to a autometer gauge with three prong marked g for ground s and I.

[DamTriton]

G is ground, S is sender, and I is instrument lights.

With the tank sender try measuring the resistance between the pins and from the pins to earth with about a 1/4 of a tank of fuel.

pin 1 to pin 2
pin 1 to earth
pin 2 to earth

(Quote with figures next to measurements)

At some point there would be a stabilised voltage fed to the sender, usually from the same source as supplies the temperature sender for the engine. This is likely to be needed at the tank sender to set up the voltage divider to derive the full/empty status of the tank by the gauge. You may need to peel a bit of this from the back of the temp gauge.

This is what we are looking for...

___ stabilised voltage from temp gauge to one of the pins of the sender
|
|
|___ the other pin of the sender to gauge "S" pin
|
|
|___Earth

[howsie]

Are you sure I would be instrument lights as light has its own two wires for it

[DamTriton]

Are you sure I would be instrument lights as light has its own two wires for it

If it has its own instrument lights then "I" would be ignition (ie switched power). I was simply going on what was told.

Is the fuel tank steel and have its own earth? Does the sender unit mounting plate have an earth if it is a plastic tank?

(I can't see anything)

[howsie]

Tank is steel. Whoever did install is dumbass so wires are everywhere so can't tell what's earthen. So far as I've figured out I is indeed ignition s goes to sender. G however it says to send to ground on tank.

This info though is for normal fuel wiring. On a gas car would this go to the other prong on the sender.

So prong for 0 ohm reading to g on gauge, prong for 90ohm (full) reading to s on gauge and I to ignition source.

[howsie]

Ok got it kinda going g on gauge is its own ground, s goes to right prong on sender (full mark), left prong on sender to ground for empty mark. And i to ignition source.

Problem is both gauge and sender are brand new and are reading different levels for example half a tank on gauge is 1/3 tank on sender. Both are defiantly 0 to 90ohm.

However 1/3 tank on sender is half way between full and empty. This is a short sweep sender maybe I need a full sweep type to get a proper reading.

Any ideas on this.