M42 pinout for swapping to a 325e chassis..

[lolcantturn]

Doing a M42 swap to a 325e chassis next weekend, it's the round c101 connector. I'm curious if someone has the M42 pinout? I've done a couple of M50 swaps so as long as I can get the pinout chart, wiring it will be cake. Thanks guys!

[lolcantturn]

bbamp

[K1CKBAC]

I had a M42 swapped into a 91 325i. You mean the pin out from engine or body? If you mean the motor, it was a direct plug and play into the 91 325i chassis harness. You can use the wiring diagram of a 91 325i chassis harness to assist you on the pin out of a M42 motor. Just in case, the chassis wiring on a 325e is different than a 91 325i even though they are both the C101 round connector but I'm sure you know that.

[lolcantturn]

I had a M42 swapped into a 91 325i. You mean the pin out from engine or body? If you mean the motor, it was a direct plug and play into the 91 325i chassis harness. You can use the wiring diagram of a 91 325i chassis harness to assist you on the pin out of a M42 motor. Just in case, the chassis wiring on a 325e is different than a 91 325i even though they are both the C101 round connector but I'm sure you know that.

I know the 325e and the 325i are different because of the C104 that runs into the glovebox with the 325e, which if I'm not mistaken is
1. Tach
2. VSS
3. Road speed

In that case, the M42 engine harness mated to the 325E chassis harness SHOULD start the car, minus the tach, VSS, and road speed? '


Something doesn't seem right, it heard it's not plug and play?

[K1CKBAC]

The M42 plugs right into the 91 325i chassis harness. The pins are in the correct position as well. Double check to see if the pins on the 325e are in the position as a 91 325i. The chassis harness from a 87 325i is different than a 91 325i if I remember correctly. I believe I remember an individual who swapped a m42 into an early model fried some wires because the pins were in a different position. That or the car didn't start. You can also look at the chassis wiring of a 318is to help.

[bmwm42]

they are not plug and plug you have to reroute the pins there is a thread about it either here on r3v or m42club

[lolcantturn]

The M42 plugs right into the 91 325i chassis harness. The pins are in the correct position as well. Double check to see if the pins on the 325e are in the position as a 91 325i. The chassis harness from a 87 325i is different than a 91 325i if I remember correctly. I believe I remember an individual who swapped a m42 into an early model fried some wires because the pins were in a different position. That or the car didn't start. You can also look at the chassis wiring of a 318is to help.

they are not plug and plug you have to reroute the pins there is a thread about it either here on r3v or m42club

Thanks guys, I'll look into it

[TobyB]

Check pin 20; if one side's green and the other's red, then yes, you get smoke.
Clip green wire on chassis side, you will be happier.

If they're both red, you're good. And yes, the vss (which IS road speed) and tach wires
need to be carried out of the 325e and mated to the engine harness... insulate the third
green wire, as it's hot.

t

[lolcantturn]

Check pin 20; if one side's green and the other's red, then yes, you get smoke.
Clip green wire on chassis side, you will be happier.

If they're both red, you're good. And yes, the vss (which IS road speed) and tach wires
need to be carried out of the 325e and mated to the engine harness... insulate the third
green wire, as it's hot.

t

So the C101 is plug and play besides the ABS? Just plugging it should make the car start?

[TobyB]

"Probably" as long as the chassis doesn't have a green on pin 20.

I say 'probably' because all the essential engine functions stay in the same places
on c101, but it's been a while since I looked at the M42 diagram... oh, and it's for an E36, too...

t

[lolcantturn]

"Probably" as long as the chassis doesn't have a green on pin 20.

I say 'probably' because all the essential engine functions stay in the same places
on c101, but it's been a while since I looked at the M42 diagram... oh, and it's for an E36, too...

t

I figured it would be somewhat plug and play with the exception of the C104. I'll plug it in, snip pin 20, and see if the engine will start.