I can't seem to fix the problem at my fuel gauge. At full, it reads 3/4 tank.

I have swapped out the Anti-Slosh Module. No effect. I even tried jumping pins between green and black, no difference.

I swapped out the fuel gauge itself with no effect. I even tried adding grounds to the back of the instrument panel, without any effect.

The ohms meter reads 48.8 ohms when I read the fuel sender at the back of the tank. Not sure what the range is supposed to be.Then I took some readings from the anti-slosh module, connecting the black probe at the ground wire, and then the negative battery post as a check, and red probe at:

1. Brown/Pink (Fuel Level) wire showed 55 mili-volts - The wiring diagram says Empty Tank 12V; Full Tank 1V
2. Light Green Wire (Fuel Level) - showed 14.6 mili-volts, diagram shows Tank Empty 12V; Full Tank 1V
3. Light Green/Orange Wire (Low Fuel Level) - shows 11.61 volts… the diagram again, shows Tank Empty 12V; Full Tank 1V
4. White Wire (Ignition Switched Power) - shows 11.66 volts - Key off open circuit, key on 12v (key was on)

I checked Black wire at AntiSlosh to Ground post on Battery - 0 ohms
Black wire at AntiSlosh to black wire at Sender - 90 ohms
Black wire at Sender to Ground post on battery - 0 ohms

I then checked green wire at the sender and the green wire at the anti-slosh - 0 ohms

White wire at antislosh to positive power post, with key on - 5.8 ohms

I'm at my wits end with this.


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I think the sender range is supposed to be 25-250 ohms. You might have a bad sender.

 

I've replaced that sender as well....forgot to mention that.

I’ve tied the battery negative post directly to the sender post as well as the sender wire and the negative wire on the antislosh module, all at the same time…no difference!

This cannot possibly be a grounding issue anymore.

I swapped the Load and Aux Load Relays behind the dash, just in case there was something funky there…no change.

What is left to check? I believe it can only be the instrument panel flexible circuit?

UPDATE 2:

I even checked the ohms between Green/Orange wire at AntiSlosh module to Pin 9 at the instrument panel. I have about 0.9 ohms. (I ran a few alligator clips and about 40’ of coiled wire to make it work) I’m going to put some cleaner on the pins…

I then checked the ohms from the pin socket to the gauge post - 0 ohms.

 

If I pull the green wire off of the sender and ground the wire to the battery, the gauge goes to F. That’s the first time I’ve seen it past 3/4 in years… Everything else was plugged in as it was supposed to be.

 

Read the Great Palm on this problem. It is very likely the electrical path between the blue flexible circuit board and the actual gauge. The volts have to go through a very poor set of contacts. I followed Palm's advice and fixed mine.

 

Went through the guide....I had already attempted most all of this, except taking the gauge out and cleaning up the inside of the panel contact.

The back side of this all looks like it’s plastic though. I can’t see any exposed copper for conductivity.

Heres a pic:

 

I have not looked at a facelift gauge, but the contacts between the circuit board and inside the prefacelift gauges are the problem. As it goes to full when you give it the full volts blast, it has to be an electrical pathway problem.

 

Greg In France,

I put a multimeter in on the relevant three contacts, and then the four other known ground points, and I pulled a 0.00 ohm for each read.

When I grounded the green wire at the sender, it went to F, so the gauge is capable, so I now have to suspect it has something to do with the sender, even though it has been replaced....with an aftermarket. I looked up what I have in there, and its a Eurospare....my arch nemesis of Jaguar aftermarket parts. The OEM (?) sender that was there originally went belly up in the same manner, so it was hard to believe it was the new sender as well.

I can't get any lower than a 48 ohm reading on the sender that's in there now. I believe I have to get closer to 20 ohms, based on what the sender shows for the prefacelift, which I'm going to assume could be the same for the facelift. I can't seem to get a confirmation on the facelift ohm reading at full tank.

 

My Haynes XJ6 service manual also indicates 18-20 ohms for a full tank.