Hi, I have tried searching but have not found a definitive answer to my question.
I am just starting an m50 (from an e34) swap into my 1989 318i. I am wiring the loom myself however my coloured wires going to the C101 plug and a couple of wires on the m50 loom are in different pins to the conversion wiring diagrams I have found.
My question is if I should follow the conversion diagrams colour-colour (with the pin numbers different) or pin number-pin number (with the colours being different)
Any help would be greatly appreciated!
M50 Swap Wiring loom question
Moderator: martauto
- Brianmoooore
- E30 Zone Team Member

- Posts: 49358
- Joined: Mon Jan 10, 2005 11:00 pm
This help? From a M50 E34 conversion I did 12 years ago:
M50 1/ blue/white (dynamic oil level) E30 2/green/yellow
M50 2/ blue/yellw (static oil level) E30 10/blue
M50 /3 red/white (ABS) E30 20/ red/yellow
M50 4/ black/blue (aircon) E30 not used
M50 5/ black/grey (aircon) E30 not used
M50 6/ purple/grey (aircon) E30 not used
M50 7/ black/purple (drive away) E30 not used
M50 8/ grey (engine check light) E30 12/ grey
M50 9/ NC
M50 10/ NC
M50 11/ brown/yellow (water temp) E30 not used
M50 12/ brown/purple (water temp) E30 4/ brown/purple
M50 13/ green/purple(fuel pump) E30 13/ green/purple
M50 14/ black/white (speed) E30 14/ black/white
M50 15/ black/green ( unloader relays) E30 15/ black/green
M50 16/ white/yellow (Rx data) E30 not used
M50 17/ white purple (Tx data) E30 not used
M50 18/ black/yellow (starter) E30 18/ black/yellow
M50 19/ white/green (service reset) E30 11/ white/green
M50 20/ black (engine speed) E30 9/ black
M50 21/ green (ignition) E30 7 green
M50 22/ green/white E30 6/ green/white
M50 23/ brown/grey (oil pressure) E30 5/ brown/green
M50 24/ white/black (fuel rate) E30 8/ white/black
M50 25/ blue (ignition warning) E30 1/ blue
M50 1/ blue/white (dynamic oil level) E30 2/green/yellow
M50 2/ blue/yellw (static oil level) E30 10/blue
M50 /3 red/white (ABS) E30 20/ red/yellow
M50 4/ black/blue (aircon) E30 not used
M50 5/ black/grey (aircon) E30 not used
M50 6/ purple/grey (aircon) E30 not used
M50 7/ black/purple (drive away) E30 not used
M50 8/ grey (engine check light) E30 12/ grey
M50 9/ NC
M50 10/ NC
M50 11/ brown/yellow (water temp) E30 not used
M50 12/ brown/purple (water temp) E30 4/ brown/purple
M50 13/ green/purple(fuel pump) E30 13/ green/purple
M50 14/ black/white (speed) E30 14/ black/white
M50 15/ black/green ( unloader relays) E30 15/ black/green
M50 16/ white/yellow (Rx data) E30 not used
M50 17/ white purple (Tx data) E30 not used
M50 18/ black/yellow (starter) E30 18/ black/yellow
M50 19/ white/green (service reset) E30 11/ white/green
M50 20/ black (engine speed) E30 9/ black
M50 21/ green (ignition) E30 7 green
M50 22/ green/white E30 6/ green/white
M50 23/ brown/grey (oil pressure) E30 5/ brown/green
M50 24/ white/black (fuel rate) E30 8/ white/black
M50 25/ blue (ignition warning) E30 1/ blue
Thanks for that, I'm currently away for work and will check those when I'm back in town!
One other question though, with pins 4, 5, 6 on the M50 side for aircon not being used, will the aircon work without these connected if I'm using the m50 compressor with the rest of the e30 system? or will some of these need to be connected?
One other question though, with pins 4, 5, 6 on the M50 side for aircon not being used, will the aircon work without these connected if I'm using the m50 compressor with the rest of the e30 system? or will some of these need to be connected?

