Help swap won't fire

[FireFight]

edit: check that the secondary power wire in the power relay block has +12V. If the fusible link blew, it won't have power, and the ECU draws all of its power from that.

I have three large gauge wires coming out battery side.
The largest gauge red wire and the smaller gauge I have on the pos. Battery cable, then on the ground the double brown wire is attached.

Then both the positive wires tie into the starter lead as well as the alt. Wire and the wire to the fuse box

Am I understand you right that there is a fuseable link in line with the smaller gauge wire in the engine harness? Or are you talking about the fuseable link in the trunk, if so this is a 318i so I have the fun battery in the bay

[kronus]

ah right, battery in the bay, no fusible link. scratch all that.

what did you connect the fat red wire that comes out of the fusebox to? It should be connected to the positive lug on the battery as well.

[FireFight]

That one goes down to the starter and is bolted up to the same wires that are attached to the battery.

[FireFight]

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[kronus]

that all sounds correct.

at this point I'd disconnect the ECU, grab a multimeter and verify that all the places that need +12V in the connector are getting it and all the places that need to be grounded are getting it as well.

[kronus]

What does VSS do for my cluster? I thought speed was from the diff and tach is coming in from c104

VSS is a signal from the cluster to the ECU. The diff signal goes only to the cluster, the ECU doesn't see it at all unless you hook up VSS.

I think it's used for coasting vs. stopped idle speeds and maybe something else. The ECU will complain if it doesn't see it, I know that.

[FireFight]

that all sounds correct.

at this point I'd disconnect the ECU, grab a multimeter and verify that all the places that need +12V in the connector are getting it and all the places that need to be grounded are getting it as well.

In the e30 Bentley they have an easy to follow list but for 24v I only have a e34 one and it's not as clear do you know a link to the pin out numbers and which need to be which?

[FireFight]

VSS is a signal from the cluster to the ECU. The diff signal goes only to the cluster, the ECU doesn't see it at all unless you hook up VSS.

I think it's used for coasting vs. stopped idle speeds and maybe something else. The ECU will complain if it doesn't see it, I know that.

that's good to know, I'll tap that one in to the third unused c104 so I don't have to route another chuck or wires

[FireFight]

I went though and found that pins 6,7,15,28,34,44,45,55,71 are grounded of those 15,44,45, and 71 are not grounded but the ecu could be supplying the ground once it's plugged in.
The reason I bring up that possibility is because pin 54 is main power supply, and with the ecu unplugged it gives a slight glow with a test light of ground, on both the DME plug side and pin 87 on the main relay.
Once the DME is plugged in, and the main relay is still unplugged pin87 has lost its slight ground and has no charge in either direction, and once I plug in the relay I found that power is going though the relay and getting power to the wire that goes to pin 87 so I can assume that with the ecu plugged in, then I should be getting the power to the dme

the pin numbers may be wrong, Im finding contradicting info on which pin is "pin 1"

[FireFight]

Double post