Fuel gauge wiring problem

XK
1

Greetings All,

I’m new here and was hoping someone could help me. I’m working on my girlfriend’s fathers '53 XK120. The fuel tank was leaking when he got it so I took it out and had it repaired and lined. The fuel gauge never worked so I ordered a new fuel sending unit, hose, etc., installation went fine but the fuel gauge still isn’t working. Caveat: I don’t know a whole lot about Jaguars other than they are a blast to drive.

So I found your forum and read several posts but didn’t find the answers I was looking for. I pulled out the dash to see the wires and it looks as if someone didn’t some repairs or modifications to the wiring and there were some freyed and exposed wires. What I found was that there were only two wires hooked to the fuel gauge and the schematic shows three. What I’m planning to do is replace some of the damaged wires and then figure out which wires are which and put it all back together according to the wiring diagram.

The questions I have are:

On the wiring diagram there are the letters R (wire 19), T (wire 13) and B (wire 17) on the terminals, what do they stand for?

On the picture I’ve added I labeled the terminals A, B and C and I was wonder what they would correspond to on the wiring schematic, for example: B = T (not that that in necessarily correct)?

Thanks for any help you can provide.

53-jag-fuel-gauge
53-jag-fuel-gauge1200×1338 225 KB

2

You can test the gauge, by grounding the “hot” side of the sending unit wire: only momentary, and the gauge should show full.

That will help you localize the issue.

3

Hi Kevin,

This post has a link that gives you more info than you probably need: XK 150 Fuel Sender.

Good luck,
Clive

4

Welcome Kevin.
First let’s be sure you are working from the right wiring diagram.
Early cars have two level sending units, one in the fuel tank and one in the oil sump on the right hand side, and a changeover switch on the dashboard, where later cars do not have the oil sender. OTS and FHC may have different color wires to the gauge. So use a diagram that matches what is on your car.
The sending unit in the fuel tank has two terminals (labeled T and W) and two wires; the green/black one to (W)indings operates the level needle and the green/yellow one to (T)erminal operates the low level light bulb, by connecting inside there to ground, so be sure your tank is grounded.
If your gauge is behaving strange it may be you have these two wires on the wrong terminals.
The terminals on the gauge should be labeled R for Reserve (green/yellow) and B for Battery (green), with T being in the center and not labeled.