Right, while tracing the alternator whine in my octy (yup its still there), I noticed that the "ignition +12V" connector for my amp is registering 1.3V when the radio is turned off and the key is out of the ignition. Can anyone put a multimeter across theirs and let me know the result?

I've tried 2 different earthing points and still have the whine...

1st....earthing point near the rear lighning cluster

2nd....seat belt bolt

I've found another point on the pillar seperating the front and back seats and hope to try that next weekend. After that if it doesn't work, I plan to run a cable to a common ground with the headunit and the amp.

Any suggestions?

Do you mean the live that switches the amp on?

How long is your earth lead? And it is the same gauge as the supply right?

Yup thats the one. The earth lead currently is about 0.5m and is the same guage as the power cable coming from the battery

Half a meter is a bit long for an earth lead I think. Need to find a closer good earth point to the amp which will help.

I created my own earthing point.

Drilled a hole though the boot floor near the ns light cluster (where I could get to it from below), dremmeled the paint so it was really shiny and then put a 10mm bolt through it. Cured my whine completely

I created my own earthing point.

Drilled a hole though the boot floor near the ns light cluster (where I could get to it from below)' date=' dremmeled the paint so it was really shiny and then put a 10mm bolt through it. Cured my whine completely [/quote']

I'd prefer not to take a drill to my pride and joy! Anyone have any other earth/ground point that I might avail of? BTW the amp is located at the passenger side of the boot.

Leons have a factory earthing point behind the carpet at the side of the boot on the passenger side - have you removed the carpet to see if this is the same on the Octy?