'85 325e receives an M42

[Rogan]

Ok, so here's the dealio.. I picked up an E30 on the cheap.. motor was busted, interior gone, etc.. Friend had an M42 laying around from his swap.
so we got it in, and I'm working on the harness conversion from the round 'late E30' plug to the 'early square' one..

Square plug is 19-pin plug with 8 blanks.
Round plug is 20 pin with a few blanks; don't remember exactly how many off-hand.

Well, I wired the pigtail to the square plug, and matched pin for pin, in relation to their function (i.e. '85 pin16 to '91 pin5 = oil pressure) and so on..

I have about 7 wires left over from the round plug, that have no home; most are sensors I believe. All other wires that have been mated were color-for-color, gauge-for-gauge..

Tracing these remaining wires back to inside the round plug, they go to pins that are considered 'empty', per the wiring schematics from TIS.

Ex. pins 14, 15 = blank per schematics, yet both have wires... :roll:

Q#1: does anyone have ACCURATE wiring for these plugs?

Q#2: replacing the 325e cluster with an iS cluster... plugs appear to bbe identical... "should" everything in the cluster work, with PnP operation? Or do I need to make/add wiring changes?

[Rogan]

Okay, Q2, I answered myself.

Q1, however, still has me perplexed.

In addition, I can't get the fuel pump to energize.. The relay clicks.. so, i took the relay out, and used a jumper wire to 'test' the fuel pump, across 30/87.. Pump works..

6 relays later, still cannot get it to work without the jumper..

all pins/signals are present at the relay socket: 12v const., 12v switched, ground, and signal out to pump..

Any ideas?

[Rogan]

Update:

I "think" the ground signal I am seeing in the relay harness is 'phantom' or feed-back.. After some more studying of wiring diagrams, it appears as the DME sends a 'ground' to the relay to trigger the FP, once the IGN supplies 12v to the + side of the relay coil. I don't think I'm getting that ground from the DME, because I can ground the wire to chassis, and Key On, and the relay trips..

so I'm missing some wiring somewhere.. I've got a white plug with three wires in it, in the glovebox area, by the DME that aren't plugged in. Is this for the Cruise Control, or something else? The car has OE cruise, but no control box by the DME; possibly removed by P.O.