I got my 2007 SRi CDTi on Saturday. I did a welcome page but it got deleted when the forum went down.
Anyway, after collecting the car, I straight away ordered HIDs, and LEDs for the sidelights and number plate before reading this forum...! Silly mistake.
I read everything about the LEDs flashing so decided to try it for myself to get a better understanding - you're all right, they flash after turning lights off, locking car etc etc.
Now, me being me, I can't just bung filament bulbs back in and forget about it, so I've had a think and come up with a 'theory', but I'm no electrician so would like advice from you guys please!
The LEDs I've got have built in resistors which prevent the error warning on the dash no problem, so why do they flash?
People say that it's because the bulb checking system sends pulses of current round the car to check the bulbs every few seconds, and this current is very small, not enough to illuminate a filament bulb, but enough to illuminate an LED.
If you fit a capacitor in parallel with the LED bulb, the capacitor should store all the current that's being sent round then discharge the current when the lights are next turned on.
The only downside, if this works, would be that when you turn off your lights, the capacitor will discharge before the LED goes out, so the LED will stay lit for approx half a second or so. Not much of an issue really.
I looked online earlier and with the help of a Yahoo answer, I did some very approximate calculations and it would appear that for the LEDs to stay on for 0.5seconds after turning off, we would need approximately a 900uF (micro Farad) capacitor in parallel with each LED.
Only thing is though, I'm not sure if this is enough capacitance to store the current from the bulb-check.
Or, when the capacitor fills up, for example on a long journey with lights off, will the bulbs flash intermittently, but at much greater intervals than without the capacitor?
Like I say, this is a theory that my non-electrically-minded mind has come up with, so no guarantees it will work, but I'll be giving it a go in the next couple of weeks anyway.
You can buy capacitors and Scotchloks from RS Components so if you want to give it a go, feel free!
Or if you have advice like... 'don't be stupid, that would never work', or 'you're a genius', you'll put my mind at rest!