07-06-2024, 10:28 PM
Hi Denis
I attach diagrams of the four positions of the PLC2 switch, showing what is happening internally in each position of the outer lighting/charging section.
PLC2 Switch 1.jpg (Size: 73.98 KB / Downloads: 412)
PLC2 Switch 2.jpg (Size: 74 KB / Downloads: 412)
The fuel gauge runs from the Auxiliary Fuse, which is fed from the output of the central ignition switch via a white wire. This same terminal feeds the live side of the ignition coil via another white wire. The fuel gauge thus only comes on when the key is turned in the ignition switch, it should not be affected by the position of the lighting/charging outer switch.
If turning on the headlamps produces a change in fuel gauge behaviour, it's a sign that the earthing from body/chassis back to the battery is not fully effective. If there is no separate earth strap for this purpose I suggest you fit one. It's not a good idea to rely on incidental earths via the copper petrol pipe and oil pressure gauge pipe as these are not reliable.
See my re-drawn wiring diagram here: http://www.da7c.co.uk/technical_torque_a...4%20A4.pdf
I attach diagrams of the four positions of the PLC2 switch, showing what is happening internally in each position of the outer lighting/charging section.
PLC2 Switch 1.jpg (Size: 73.98 KB / Downloads: 412)
PLC2 Switch 2.jpg (Size: 74 KB / Downloads: 412)
The fuel gauge runs from the Auxiliary Fuse, which is fed from the output of the central ignition switch via a white wire. This same terminal feeds the live side of the ignition coil via another white wire. The fuel gauge thus only comes on when the key is turned in the ignition switch, it should not be affected by the position of the lighting/charging outer switch.
If turning on the headlamps produces a change in fuel gauge behaviour, it's a sign that the earthing from body/chassis back to the battery is not fully effective. If there is no separate earth strap for this purpose I suggest you fit one. It's not a good idea to rely on incidental earths via the copper petrol pipe and oil pressure gauge pipe as these are not reliable.
See my re-drawn wiring diagram here: http://www.da7c.co.uk/technical_torque_a...4%20A4.pdf