Need help finding turn signal relay and part number

squidzilla · #1 02-12-2017, 12:25 PM

I have done several searches and the closest I can get to the answer I need is that the relay is in or behind the headlight. Has anyone changed this out themselves before? I also can not find the part number on realoem and can not even find a picture of what the part looks like. I would prefer to have the part in my hand before I attempt this.

It is for my 01 m54 x5. Left Signal.

Qsilver7 · #2 02-12-2017, 05:47 PM

All exterior lighting is under the control of the LCM. There are no separate "relays" for the headlights (see 2nd paragraph in 1st image below). BMW eliminated fuses & relays and incorporated these functions into the LM...which debuted in the e38...which then morphed into the LCM & it's various iterations:

squidzilla · #3 02-12-2017, 10:42 PM

So it is not a relay in the headlight that needs to be replaced for a fast blinking turn signal then. OK. Hmm...

Qsilver7 · #4 02-13-2017, 12:36 AM

A fast blinking turn signal usually indicates that one of the bulbs is blown. The blown bulb causes a change in resistance...so the indicator blinks faster than normal.

Make sure all bulbs on the side that is blinking fast is intact and working. If you have dual filament bulbs (in either front or rear)...then you need to make sure that both filaments in those bulbs are intact.

See REPLACEMENT LIGHTING info above about the LCM III...this is the reason why all bulbs need to be intact...because if some bulbs burn out...other bulbs can be used instead...but this still will cause the fast blinking due to a drop in resistance.

wpoll · #5 02-13-2017, 06:25 AM

Quote:

Originally Posted by Qsilver7

A fast blinking turn signal usually indicates that one of the bulbs is blown. The blown bulb causes a change in resistance...so the indicator blinks faster than normal.

Old school thermal flasher devices used the total electrical load (current, in amps) to control the flash rate, via a heated element. Once a signal bulb blew, the electrical load changed and therefore so did the flash rate. This response has become known as an indication of a failed signal bulb but I suspect it was a happy coincidence and not intentional.

Roll forward to today's modern LCM-III controlled signal lamps and a flash rate change (on the cluster indicator only) to indicate a failed signal bulb is simply the modern incarnation of what car owners/drivers have experienced for many years and expect to see. The LCM is well "aware" of the failed lamp via hot and cold monitoring, which is in effect measuring the electrical load, kinda like the old thermal flasher circuit, and could just as easily start whistling Dixie or any other form of alert function. Rapid flashing is what drivers expect so that's what they get. But only on the cluster - unlike the old thermal flashers that actually flashed the signal lamps faster too.

And I love that we still get the "tick tack" sound when the signals are on. Same deal - had it for years (with mechanical contacts opening and closing) so we would miss it with modern electronics. I guess it also reminds us we have signals operating too.

squidzilla · #6 02-13-2017, 07:37 PM

Thanks for the responses. It blinks fast but still shows a flashing bulb in the front and back. Just blinks fast. The funny things is when the x gets hot enough it goes back to normal speed. Seems like the cold is making it do it.

Doru · #7 02-14-2017, 07:13 PM

On my ex-e39 I know when the bulb sockets started getting corroded, one would get similar symptoms.
Just pull the bulbs out and gently clean with a fine grit sandpaper - I'm 99.99% sure this will cure the issue.
Some guys were using non-OEM bulbs, and the socket material/coating was bad giving similar symptoms.

0.02