Faulty fuel gauge 1999 Gu patrol td42

[Campy]

I have a 1999 td42 patrol which I have cut Ito a dual cab and had a double in dash sound system fitted.now the fuel gauge won't read right.when I turn the ignition on the gauge reads right until the engine starts then the needle gets a mind of its own and fluctuates badly.any ideas would be greatly apreciated.

[the evil twin]

What brand of double din head unit?... Name brand or Ebay special?

Did you fit it or a sound mob like Alberts or whoever?

The earthing of the GU dash, instrument cluster, power antenna and head units is problematic at the best of times and it is also easy to get the 'ign on' and 'battery' power wires rrse about when adding aftermarket bits.

I would disconnect the head unit and see if the problem goes away or is still present and work it out from there

[Yendor]

Have you installed a battery in the tray? What charging system did you use?. Where is the main earth for the battery connected to? the chassis?

Regardless it won’t hurt to run another earth lead from the vehicle’s main cranking battery to the chassis.

[Campy]

What brand of double din head unit?... Name brand or Ebay special?

Did you fit it or a sound mob like Alberts or whoever?

The earthing of the GU dash, instrument cluster, power antenna and head units is problematic at the best of times and it is also easy to get the 'ign on' and 'battery' power wires rrse about when adding aftermarket bits.

I would disconnect the head unit and see if the problem goes away or is still present and work it out from there

Yeah mate it is an alpine system and was fitted by a licenced installer

[Campy]

Yeah mate nothing in the engine bay has changed

[Yendor]

Yeah mate nothing in the engine bay has changed

?. Try the earth lead. As a test use jumper leads and see if the problem goes away.