Hi all I m in the middle of this swap and like to clarify:
Do the M40 316i fuel pump feed the thirsty M20 325i?
M40b16 to M20B25 swap
Moderator: martauto
Thanks for the reply jmc
Another question
What are the 2 wires connected to the positive battery terminal?
On the M20 body there are still 2 wires while On the M40 body I ended up with only 1 wire because the other wire comes out with the harness
Another question
What are the 2 wires connected to the positive battery terminal?
On the M20 body there are still 2 wires while On the M40 body I ended up with only 1 wire because the other wire comes out with the harness
- Brianmoooore
- E30 Zone Team Member

- Posts: 49358
- Joined: Mon Jan 10, 2005 11:00 pm
M20 and M40 should both have at least two wires going to the battery + terminal, in addition to the large cable to the starter motor. One of these feeds the engine wiring loom, and the other is the power feed to the fusebox and ignition switch.
There will be a third wire on cars with ABS, that powers the ABS pump motor.
There will be a third wire on cars with ABS, that powers the ABS pump motor.


