hazard light switching on on it's own?

[shogun]

I had a similar case 2 years ago. Hazard lights went on while driving. Took me quite some time to find the culrpit. Cleaned the hazard switch and other things. Nothing helped.
Finally I replaced the crash control module in the fuse box and the problem was solved. It is the brown one right of the CCM.
This crash control module has the following function in case of a crash:
switching on courtesy lights, unlocks door locks, switching off fuel pump(s)
http://www.nmia.com/~dgnrg/page_22a.htm
pic is from gale's page.

[ukm5]

on the E34 its located under the rear seat just next to the tunnel, connected direct onto the bodywork

[Kalevera]

on the E34 its located under the rear seat just next to the tunnel, connected direct onto the bodywork
Actually, Shogun's correct on this one, although it depends on the MY of the car as to exact location under the hood.

best, whit

[shogun]

The crash sensor sits under the rear seat. This brown module or relay sits in the fuese box. Actually I just have it here on my desk. Correct name in German printed on it:

Crash-Alarm-Geber 12V-, Teilnr. 1 384 732 (on the other side is printed 84552N). The new p/n I got is 6135 8364 691.

Man, I tell you, that worried me about 3 months and I couldn't find it.
Here you can see the inside parts

http://www.pagaduan.org/bmwe32/index.html