97 XK8,
My fuel gauge always reads 3/4 full with the ignition on and 0 with it off. So it's not stuck. Any thoughts?

 

Are you sure your car just doesn't have 3/4 of a tank? Could be a broken fuel sensor. I would fill it up and see if it shows full or stays at 3/4.

 

Yup, that's how I knew. I filled up. It showed 3/4. So drove about 100 km. No change.
Probably the sensor

 

Take the sender out ...Move the float up and down and see if the gauge follows ..if it does not the sender is faulty. When fitting new one do the same test before you fit it . Sometimes you can repair it but it does not sound like a sunken float.

 

I was pleased to see how accessible the sender is, though without the gauge working, I'll have to be careful with the fuel level. I don't want to run dry for sure, but don't want to open it up before the fuel level is blow the sender.
Finally, a problem with the jag that's a simple fix. LOL

 

You can select Range on the information display on the speedometer by pressing the button on the end of the indicator stalk - if this is also stuck on the approx. distance for a 3/4 full tank then you know it's the sender.

 

Aha! that should at least give me some info. If the range doesn't drop when I'm out and about, I'll know that the float is stuck and I'll still need to find a way to tell when the fuel level is low enough to pull the sender.
OK thanx

 

This is a test you can do to verify if the sending unit is working.
link. JagRepair.com - Jaguar Repair Information Resource

Gus
JagRepair.com - Jaguar Repair Information Resource

 

Lucas in the day made a box with a dial for E 1/2 F to attach for testing but seperate resistors are just as good.

 

Got lucky with Pandora!....no, not that!, I used a resistor substitution box to check my gauge, and it looked like I needed a new sender, but when I hooked it back up, it worked just fine. Great, also got my AC cooling again. Now on to the antenna mast, and front sway bar bushings.