Rear lights (inside) LED conversion

[the dutch guy]

if it still gives you problems you can put a diode on the positive side and a cap behind i (so: diode>cap>SCR) t, that will buffer the power the SCR needs and keeps enabled for seconds or even minutes depending on the size of the cap.

[maccmowers]

I was thinking about the relays and what you said, so I thought I'd just try another relay before getting into any serious electronics. So I ordered a standard 5 pin relay from my local factors, fitted it and it was exactly the same, but the relay didn't make a sound. It works, but no vibration or anything.

So I got the multimeter out and started testing what was coming from where. It turns out the positive side is battery live! It's the earth that gives the slow increase/decrease!

The earth when the lights are off has a solid 12v, and as the lights are switched on the voltage slowly decreases to 0.3v.

So I think I'm correct in thinking I now have to wire a relay with the switch wire as the negative from the BCM and make a separate earth for the LEDS. But would it need a diode with the BCM being on the negative side?