m50 with m20 starter/fuse box wiring questions

[mtech325]

Hey everyone,

I'm doing an m50 swap currently and I've ran into a bit of a snag on some of the wiring. Hopefully some of the 24v guys can give me some pointers as to where some of these wires go. I did a search, but I haven't gotten any concrete answers.

The car is a 93' 325 convertible. The motor is an m50tu and the trans/flywheel/starter setup is a g260 with shaved m20 flywheel and m20 starter. The harness I had at first was off an e34 525i, but I proceeded to go to the junkyard and pull/label an intact 94 325is manual harness for better fitment purposes.

The first of my questions is what to do about the fusebox wiring? The e36 harness has tab to be bolted down to the fuse box itself. The e30 has two wires coming off the fuse box. I checked the colors between all 3 of these wires and they are red (so they get power). Do I cap off or delete one side (e30 vs e36), and where would I connect the side I choose to go with (the starter large terminal that already has two connectors there?)




My other questions concerns the two starter wires that come off the harness itself. They seem like they should be connected to the starter on the smaller terminal (like 8mm or so). My question is can they be placed on top of each other or do they go on different locations of the starter? The connector tabs are similar but one is a little bigger than the other. Both connections have a black/yellow wire in them.



This last one is the m20 starter for reference:


Sorry for the long post, but I wanted to be as detailed as possible and not fry the wiring before trying to start the car!

Thanks in advance,

Joey

[e30austin]

The two E30 fuse box wires get connected to your hot battery terminal (meaning powered all the time.) The E36 wire there is either a ground or DME power (can't tell from the pic,) so go ahead and cut the sheathing off and see if it's red or brown. I'm going to go ahead and say that is most likely a ground, though.

It is imperative that the starter wires go in their respective places. It will be obvious what goes where when you go to install them. One is slightly bigger than the other. If you don't set those up right, either your windows/blower motor won't work, or the solenoid just won't engage.

Good luck!

[mtech325]

Thanks for the help Austin,

I think I've got it all squared away now. The convertible not having a power distribution block required some adjustments for the fuse box wires. Hopefully it starts in a few days!

[mpowerful]

I added a stinger power block to mine for that reason. I may post the details in my thread later tonight.