Wiring fuel sender to gauge

[Gordon Watkins]

I'm reconnecting wiring in my '62 T6B, 20+ years after removal. With over-spray obscuring color codes, faded/missing id tags and my vague notes, compounded by fading memory, all has created headaches requiring continuity testing of all wires to confirm correct attachments. Rodent damage doesn't help.

Right now I'm trying to figure out the connection between the fuel sender and the fuel gauge. I can find the green and brown (ground) wires in the under dash harness along with the other combo-gauge wires, but not the corresponding ends under the hood, only two loose wires connected to the sender (top mount) which were presumably cut during disassembly. Should I find a green and brown wire coming from the main loom through the firewall, (the ones which mostly connect to the fuse block) or are they somewhere else?

I have the factory workshop manual, Joe Leoni's book, and I'm making my way through Greg Bryan's Registry articles but can't find these two elusive wires. Any help is much appreciated.

[Mike Wilson]

Your '62 should have been a bottom sender unless previously changed out.

Mike

[Doug McDonnell]

And there should be a small branch harness that contains just the green and brown wires to the sender.

[Gordon Watkins]

Yes Mike, I have repair records that show my tank was replaced.

Doug, the branch harness is there under the dash but not in the trunk. I'll dig deeper but in a pinch I'll just make a new pair. I just wanted to be sure they should be located where the main harness penetrates the firewall and not some other location.

[Mike Wilson]

Sorry I missed the fact that the tank was replaced. Was the wiring also replaced or the original bottom sender wiring rerouted to the top sender? Looks for the wires in black plastic sheathing. Looking at the wiring diagram, the green wire from the sending unit on the gauge should go directly to the sending unit on the tank. Not sure where the brown ground wire lands.

Hopefully one of our electrical gurus like Greg Bryan will weigh in to correct me or clarify.

Mike

[Jim Padula]

Where does the fuel gauge get it’s 6 volt from

[Mike Wilson]

From the fuel gauge unit on the combo gauge.

Mike

[Martin Benade]

The sending unit is basically a variable resistance to ground, with ground being reliably the brown wire, or less reliably, the tank grounded to the body.

[Jim Padula]

How does the fuel gauge get powered

[Vic Skirmants]

See post #7.

[Mike Wilson]

Power to the gauges themselves comes from #15 connection on the ignition switch. Blue wire with yellow tracer.
Do the rest of your gauges work, temperature, etc.?

Mike

[Greg Bryan]

Power for the gauges and warning lights comes from switched terminal 15 on the ignition switch - blue/yellow wire. See it connected to the + terminal of the fuel gauge. Green wire goes on the G terminal. Since the T6 body, the fuel gauge circuit has it's own ground to make the gauge more accurate and/or reliable, I suppose. The diagram below is for the C, so your car will not have the hand brake switch and maybe not the parking light on warning light.
Good luck!

[Al Zim]

The 356 is plagued with a fuel gauge that jumps around in normal use. This can easily remedied we sell as stabilizer device that can easily be snapped on the the fuel gauge and the wire from the tank sender. al zim
www.allzim.com

[Jim Liberty]

I try to use original dated senders. I take a new after market sender and graft the top of the original dated on. Takes a little time, but if you are careful, only the thickness is a giveaway. Did this on my Amelia Island 1955 Continental. Was not caught. ....Jim

[ScottBerry]

I am cleaning up my fuel sender wiring. The end with an odd plastic end looks damaged or is it correct?Should there be more of a protruding wire nub at the end. I am assuming this plugs into the fuel garage. Is there a name for this part and is it available to buy? Thanks