Another fuel gauge question.

[sogood]

Many of the gauges on my Wellcraft had been replaced with Faria instruments and I finished off things by replacing the rest, including the fuel gauge. However, when I switch on the ignition the gauge jumps to full, despite the tank being empty.
This happens even with the sender at the tank totally disconnected. I tried every possible combination of connections at the gauge, with the same result, including blowing the ignition fuse on one occasion.

When I removed the sender, still wired up, it sent the gauge through its full movement when it was moved by hand. So any thoughts much appreciated. I figure the sender is good but there may be an issue with the wiring behind the dash. I have a multi meter and am familiar with tracing wires etc. Thanks.

 

[Scott Danforth]

your signal wire from the sender is ground out somewhere or you have the wrong gauge for your sender

it would be the pink wire for the sender. black is ground, dark blue is for the light and the purple wire is the + supply for the gauge - standard SAE wiring color codes

the gauge works with a variable resistance to ground, with a full short to ground pegging the gauge.

however since you played musical wires and even blew the ignition fuse, you may have shorted the gauge.

 

[alldodge]

How many wires are on the sender?

 

[sogood]

After connecting the gauge as per the instructions supplied with it, I then tried my alternate connections, resulting in blowing a fuse. There are 3 wires at the sender. Pink, black and green. FWIW the tank is aluminium.

 

[alldodge]

Was wondering if the sender also had power applied to it. Replaced some senders on a Regal which used them. Being a Black and Green in the mix, this is probably not the case. Black Ground and Green should go back to buss bar which is also grounded via a galvanic isolator

Remove the Green wire and turn key ON, then check for any voltage between Black and Green, there shouldn't be any

The USA standard is 240 ohms empty and 30 ohms full. With the sender removed the gauge works fine, but installed it pegs full, correct?

 

[Scott Danforth]

After connecting the gauge as per the instructions supplied with it, I then tried my alternate connections, resulting in blowing a fuse. There are 3 wires at the sender. Pink, black and green. FWIW the tank is aluminium.

Pink is your signal that goes to the gauge, black is ground that goes to your wiring harness ground bussI, green is a bonding wire that goes to your bonding terminal strip

 

[Fed]

European / American / gauge / sender mismatch.