Bad ground starboard fuel gauge

[jclays]

Mainship 1997/350
Fuel gauge bounced around when I bought the boat 3 years ago then stopped registering. Figured a poor ground. Cleaned off all connections at the sending unit and anywhere I could find. No go. Went under the dash and applied a jumper from the instrument hot lead to ground . Works! Can I run it like this?

 

[Delta Riverat]

What you described is a short circuit.

 

[Comodave]

When you say the “hot lead” are you referring to +12 volts? If so then running a lead to ground is indeed a short and that isn’t good. You should blow a fuse or trip a breaker somewhere.

 

[jclays]

Yes
Grn to + lead. Needle on the gauge moved to full.

 

[jclays]

Yes jumper to + behind gauge other end to gen. Needle on gauge moved to full. Tank is full.

 

[Comodave]

It may work but you don’t want to short +12 volts to ground. That is asking for melted wiring if it doesn’t blow a fuse or trip a breaker.

 

[Delta Riverat]

I'd check it with a meter. Maybe the wiring is reversed? Generally the +V is fed to the gauge, the sender is on the other post and the sender is grounded.

 

[jclays]

I misspoke. The wire I touched with the ground jumper was the wire from the sender to gauge. Not to the hot lead to the gauge.

 

[Comodave]

That is better. Sounds like maybe you have an open wire somewhere or a bad connection. Maybe try running a new wire over the deck from the sender to the gauge, then if it works you have narrowed the problem down.

 

[jclays]

Would the gauge work if grounded in this fashion

 

[sean9c]

You've shorted your sender to ground. It'll not read anything but full, irrespective of tank level.

 

[Comodave]

What I mean is run a temporary wire from the gauge to the sender and see if that fixes it. If it does then you know which wire is bad and troubleshoot it.

 

[jclays]

Thanks