PLC 2 problem

[Tiger]

After wiring the rear lights on my Ruby 
Rear lights only work with switch on headlight position.
With little of no available replacements available has anyone converted to PLC 5 
Or anyone other ideas.
PS As you know repairing PLC 2 switches NOT EASY
Regards
            Tim

[JonE]

what terminals ARE being used for lighting as there are a number of different variants?

Do the sides work on first position? As if they do, then something is amiss - but not with switch, surely?

[John Cornforth]

Hi Tiger

The PLC2 has 3 sections:

Ignition Switch
Lighting Switch
Charge Rate Switch (Summer Half/Winter Full)

I'm pretty sure you could substitute the later PLC5, but it doesn't have the Charge Rate section. You'd then have to link the generator to give full rate all the time, or fit a separate charge rate switch (a simple on/off switch) somewhere.

However, I can't help feeling that your sidelight problem is due to mis-wiring somewhere, rather than a fault in the original PLC2. These are pretty chunkily made inside, and normally soldier on for a long time. See:

http://www.da7c.co.uk/technical_torque_a...rubies.htm

for how it was wired originally.

[AustinWood]

Does the PLC have separate outlets for Tail lights & sidelights?
The SM5 does and the sidelights turn off when the headlights are on. The sidelights are in the headlights and therefore not needed when headlights on.
Saves current - Every Little Helps

[John Cornforth]

Hi

The PLC2 in the Ruby has both the Side and Tail lamps connected to its "T" terminal, which is energised in both Side and Head settings.

However, there is also an unused "L" terminal which is only energised in the Side setting. Presumably, Lucas provided this for applications in other vehicles which had the side lamps within the headlamps.

[Tiger]

many thanks for the replies.
All sidelights connected to the T terminal.
This is only energised when switch is set to headlights.
I will investigate the L terminal.
PS probably be OK to have only one working position for all lights.
There was no wiring when I purchased the car.
Regards
Tim

---

Sorry I forgot to mention.
Wired the car following explicitly Mr Cornforth’s excellent diagram.

[Tiger]

L terminal al not activated in switch position