M20b20 wiring help!!!

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E30 Zone Newbie
E30 Zone Newbie
Posts: 1
Joined: Mon Apr 22, 2019 6:49 pm

Mon Apr 22, 2019 7:27 pm

Hi guys,

Been a few years since I’ve touched my e30. Finally getting round to sorting it out I’m half way through an engine swap. I originally pulled the m20b20 out as I had planned to do an m52b28 swap. However personal circumstances changed and I wasn’t able to continue. So I’ve recently dropped my m20 back into the car just so I can at least get it out on the road in the mean time while I source parts needed to do the m52 swap. I have pretty much everything in place but I need some help with wiring. I’m hoping this will be quite simple for someone to help with. I need to know where the loose cable for the battery connects to I can’t for the life of me remember where it connects to and I can’t find the info anywhere. ( I have spent a lot of time looking) I also have chopped a wire from the loom which I think is a power cable and also need to know where this goes and also a part number to re order one. Photos are below. I know I’ve chopped more off but that was to make a connecter for the m52 I have a new loom but don’t seem to have these cables with it.
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E30 Zone Team Member
E30 Zone Team Member
Posts: 47577
Joined: Mon Jan 10, 2005 11:00 pm

Mon Apr 22, 2019 9:24 pm

The ring terminal on the end of the wire in pic.1 goes to the outer terminal on the starter motor solenoid.
The smaller wires attached to the battery + terminal go to the fusebox, the engine loom, and (if fitted) the ABS pump. All are plain red wires of various sizes.
The earth wires from the engine loom are brown or brown/orange, and go the the main earthing point for the battery neg. terminal on top of the RH front suspension turret.
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