After market fuel tank issues (duel fuel)

[Gq4mud]

Hi guys, how is everyone? I'm new to this site and new to 4x4s in general, late last year I Baught a 1989 gq patrol 4.2 auto lwb black on silver. Nice little rig.
Anyway I have been fixing bits and peaces on it up to bring it up to scratch which leads me onto my delema. It is one fuel fuel and runs fine on both. However the fuel gauge is stuck on past full, I have tried a different cluster in in an when I plugged it all in it read full strait away, so I then dropped the tank out and checked the sender unit which looked shagged so got a geniun one and did all modifications so it fitted in the tank and tested it all with a multi meter checking the ohms and all is working fine when the tank is out of the car.. I can plug the lines back to the tank and check that the sender is reading fine when the tank is not bolted up to the body, but as Soon as I bolt it up to the boddy the fuel gage goes to full.... Could be a bad earth?? I have checke the wireing that runs from the sender unit all the way back to we're it disappears in plastic condute at the back of the car..

This has just got me puzzled..

[Yendor]

Is the original electrical plug still used at the fuel tank? or have the wires been extended or the connector replaced?

The wires at the sender unit might be around the wrong way.

[Gq4mud]

I have checked and they are all on right..I even redid the connections from where they had to extend the cabling..

And yeh mate still using the original plug ;)

[MudRunnerTD]

Hey Gq4mud,

Welcome to the forum, I'd appreciate it if you could head over to the intro section and post up an intro about you and your rig. We like folks to say G'day before asking questions. Nice to see Yendor looking after you already.

It's like walking into a room and not saying g'day mate, its just got to be done.

Cheers MR

[Yendor]

I think when they extend the wiring they mixed the two wire up.

Now the wire from the fuel gauge is going to the body of the fuel tank, this is why when the tank is unbolted the gauge works but as soon as you bolt the tank back up to the chassis this earths the tank and cause the gauge to read full.

[Gq4mud]

Hmmm.. Ok well I'll put it on a hoyst st work and change the wires around today and let u know how I go... I see ur reasoning.. Cheers

[Gq4mud]

I think when they extend the wiring they mixed the two wire up.

Now the wire from the fuel gauge is going to the body of the fuel tank, this is why when the tank is unbolted the gauge works but as soon as you bolt the tank back up to the chassis this earths the tank and cause the gauge to read full.


Hurray!! Finally yes the wires were the wrong way around. Thank you do much for your "fresh" and stupidly simple idea that I seemed to oversea. Much appreciated ;)