8 replies to this topic

[Gatti]

Hi,

 

I drove my car at night for the first time in ages and when I put on my headlights the fuel gauge stops working but if I turn off the dash lights it works again 🤪
 

I know it must be a short somewhere but what's the best way to trace it?

[RallyRed]

Hi mate ,
LC/ LJ are cronic for bad earth return issues in the dashboard.
Typically, when you turn the lights on temp increases and oil pressire goes down ( from memory).
Others may have a fix I just learned to live with it.

[limo]

The earth from the loom goes to a screw in dash behind the amp on LC. Have to take gauge panel out to get to it. Can try cleaning connection. One car I ran another earth wire to engine. Main problem as I see is the earth connection between battery terminal and body at the radiator mounting bolt. Again can be bad connection. But from factory I reckon it's too thin and there's a voltage Drop when lights on and current increased. Just few suggestions

[Gatti]

The earth from the loom goes to a screw in dash behind the amp on LC. Have to take gauge panel out to get to it. Can try cleaning connection. One car I ran another earth wire to engine. Main problem as I see is the earth connection between battery terminal and body at the radiator mounting bolt. Again can be bad connection. But from factory I reckon it's too thin and there's a voltage Drop when lights on and current increased. Just few suggestions

 

Thanks mate.

 

I've ordered some LED bulbs for the dash that should arrive this week, so I'll have a look when I have the dash out.

[hanra]

I dont know how the little cars systems work, however with my big car, I ran a dedicated ground wire from the voltage regulator to the body. As my gauges would read incorrectly when the lights were on. 

[Rockoz]

Definitely not a short.

All the symptoms point to an earth that isnt quite right.

As it is affecting the headlights as well, you need to check there as well.

The fuel gauge going to zero points to the system using the fuel circuit, or gauge circuit to get the earth.

Check your parker earths, then the headlights. Then the earth behind the dash.

 

Cheers

 

Rob

[grumpy xu1]

I dont know how the little cars systems work, however with my big car, I ran a dedicated ground wire from the voltage regulator to the body. As my gauges would read incorrectly when the lights were on. 

The voltage stabilizer in lh & lx, is not present in lc & lj, just to stop any confusion of the voltage regulator, used in lc & 72 lj external regulator car's. Automotive power & electronics north Rockhampton Qld, do a better more stable improvement on the lh lx system. I would highly recommend it.

[hanra]

Yeah nah I used a solid state regulated 5v SMPS for my regulator.

Edited by hanra, 03 March 2020 - 07:43 PM.

[hanra]

https://www.jaycar.c...ulator/p/XC4514