engine swap electrics help please

[flat_out_kernow]

Hi everyone,
Right I'm in a bit of a mess. I bought myself a clean little 316 e30 about 9months ago and got my self a little gem. Bought a m20b25 engine, 325 axle, diff,loom and all the other pieces and began the swap. I was called away to work and ended up breaking my back .
The cars at the stage now where the bulk of it is done but I've got stuck on the wiring. I've got a mate who can help me but were both shite with electrics.

Our first big problem was due to an improper engine earth strap where we had it from the sump (where it was on the m40 engine) to the body of the car. As soon as we connected the battery with no ignition it instantly started smoking the wire that burnt out was off the oil pressure sensor (which goes up to the brown wires that are crimped together by the battery) . pin 20 was red/yellow both ends
Managed to get another loom, put it in the car. Moved the earth strap to the block. Connected the battery andddd.... No smoke! Yay. But weve got no power anywhere really. No dash lights, harrard's, fuel pumo,... Bugger..
We do have power to the starter and to the relays but not a lot anywhere else?

Where's a good place to begin? Im not back at work and for the moment my outgoings are far exceeding my income i can't afford to throw any more cash at it.

Any help would be muchly appreciated.
Thanks

[Brianmoooore]

As long as you are aware of the potential C101 pin 20 problem, then the conversion is absolutely plug and play. A good earth strap on an M20 is absolutely essential, as you now know.
Your 316i body loom makes no use of the oil level sensor signal, so leave the plug disconnected at the sensor to eliminate the possibility of a recurrence.
The most likely cause of your current problem is a poor connection of one of the smaller red wires attached to the battery + terminal. This wire supplies power to fuses 21 to 28 all to most of the relays in the fusebox, and then goes on to the ignition switch.

[flat_out_kernow]

After having a quick look yesterday were still stuck. The new loom is slightly different from my old one. On the positive terminal there is no 3 red wires. There is one red wire to the relay but that seems to be it. I'm probably been a complete bell end here lol. Thanks

[Brianmoooore]

All E30s have the large cable from the battery+ to the starter motor, plus two smaller red wires attached to the terminal. One of these goes into the engine loom, and the other goes to the fusebox. Some E30s also have a third red wire, which goes to the ABS pump.
If your car doesn't have the red wire to the fusebox, you've either 'lost' the end of it while doing the conversion, or have connected it to the earth terminal on the suspension turret by mistake.

[flat_out_kernow]

Made a bit of progress today. The 3 red wires were all on and OK but somehow we managed to put the 3 brown wires that go to a ring connector to the earth point. We connected the battery up and heard a solinoid click and we had no smoke or fire so all good there. We now have dash lights on all the time and nothing when we turn the key.

On the fuse box there is a thick (earth?) Wire with ring connector, where does that go?

Thanks for your help

[flat_out_kernow]

Also, just to clarify. Pin 20 on the c101 plug is red/yellow on the car side and a brown wire on the engine side that has been cut away and taped up. Is this correct. Thanks

[Brianmoooore]

somehow we managed to put the 3 brown wires that go to a ring connector to the earth point.

??? The brown wires with ring connectors DO go the the earthing point. All plain browns and brown/orange are earth wires on BMWs.

We connected the battery up and heard a solinoid click and we had no smoke or fire so all good there. We now have dash lights on all the time and nothing when we turn the key.

Not 100% sure, but I think you may have connected up reversed polarity, which isn't good!! Damage may have been caused.

On the fuse box there is a thick (earth?) Wire with ring connector, where does that go?

Thanks for your help

The only thick wire that comes from the fusebox and has a ring connector on it is the main positive feed to the fusebox and ignition switch. The wire should be plain red, and goes to the + battery terminal.

ALL brown and brown/orange go to earth, and ALL plain red go to the battery + terminal.

[flat_out_kernow]

I'll have a look tomorrow and see what's on. Having broke my back I'm unable to get too involved and see what's going on so am probably relaying these messages wrong.

I'm hoping its something simple but knowing my luck its fucked...

Thanks for the reply

[flat_out_kernow]

Right. Had a look at the car today and after cutting back the black cover we saw how much of a lash up we had made. We had the 3 brown wires onto the positive and had the the red wires off the fuse box not connected. Not great..
We put it back as it should and things were looking a lot better.
We now have dash lights, radio, indicators etc when the ignition is on and the car turns over lovely.
But we have no spark. We've got power to the relays and to the ECU.
Think we could of fried the ECU? Is there any way to test it.
Or what would be the next steps to check?
Thanks for your replys
We need all the help we can get

[Brianmoooore]

Think we could of fried the ECU?

Possibly depends where you had the red wire to the engine loom connected, although you would have reverse polarised the ECU on the green ignition wire the second you turned the key to the start position, via the starter solenoid winding. This wouldn't have occurred if the red wire to the fusebox had been connected.
First test is to see if the DME relay (white one on the LH inner wing bracket) clicks when you turn the ignition on. Check it by first pulling it out and plugging it back in with the ignition OFF. It should not click.
Next, turn the ignition on and pull the relay out and back in again. It should click both times.

[flat_out_kernow]

I've got a day of Physio and hospital visits tomorrow but will be able to have a look on Thursday.
Thanks for your help.
Any other advice is appreciated