LED bulbs issue

[NigelA]

I favour replacing the standing bulbs with LEDs. That's worked fine for side lights (front and back), reversing and rear fog lamps, but the indicators present a problem.

Replacing the standard indicator bulbs with 50SMD LED produced a fast flash; the same as you get with bulb failure. However, after changing back to standard bulbs I find that the brake fail light on the check panel will not go out. Also the flashing 'CHECK' indicator on the instrument panel is not cleared by pushing the brake pedal.

Is this possibly a re-set issue (by disconnecting and re-connecting the battery) or has something else gone wrong please?

Thanks in advance for any help.

[Grrrmachine]

A lot of the electrics in the car are based on resistance values - there's little in the way of control chips.

So if you switch to LEDs, or HIDs for the headlights, then the Check control panel will often throw a fault as it's not getting the resistance it expects from a standard bulb.

As for the brake light, you might have just disturbed things in the rear cluster - they're very fiddly and known for bad connections. Just wiggle the bulbs to see if it fixes things.

[jmc330i]

From memory there's an issue with fitting LED bulbs in the brake lights and brake check light working. I think its to do with the check system looking for a certain level of amps from the brake lights, but as the LEDs use much less amps than bulbs the system thinks there is bulb failure.
Less amps being drawn through the flasher unit may also be why the indicators flash fast with LEDs fitted.

Not sure why the system wouldn't function as normal once standard bulbs have been refitted, unless you have disturbed a dodgy connection in the rear cluster or have refitted an iffy bulb.

[NigelA]

Thanks, James. Much appreciated. Possibly Brian may see this and respond. He seems to be the electrics ghuru for E30s. Again, many thanks, Nigel