Wiring problems...

[E30BTR]

I'm done with google search and I'm I have a a 86 e30 and removed the m20b20 for a b25 from a 91. I can't find where the gr/br wire that is near the alternator. On my 86 harness (body side) has a plug with 3wires that connects to the engine harness next the the ecu/dme. The 91 engine harness has 5 wires are cut, what should I do with the five wires. Also when I have the ignition to the on position when I open the passenger door I hear a relay click, is this normal?



Thank you

[Farbin Kaiber]

Oil Pressure switch. I got your PM on the other forum, but figured I'd answer here.

[E30BTR]

Oil Pressure switch. I got your PM on the other forum, but figured I'd answer here.

Awesome, thanks.
Would you know about the other wires and relay?

[spdracrm3]

comfort relay

that relay in the first picture is an add on comfort relay that allows you to operate the power windows and sunroof (if its hooked up properly) with the door open and i think key out or on accy postion(thats why you here the relay click when you open the door) . it was a euro option only but with a few cars euro making it over here including M3's there are some that are surprised to find the widows/sunroof work this way .

here is a link to a post with a wiring diagram

http://forum.s14power.com/showthread.php?7266-Euro-ETM-s&p=92257#post92257

other wires in ECU harness might have been coding plug connector to allow change in mapping due to different fuel octane ratings

interesting to see your ECU on the drivers side and not above the glovebox! or is that a righthand drive car?

[Farbin Kaiber]

or is that a righthand drive car?

Ding Ding Ding, we got a winner!

[E30BTR]

Thank you for the info and yes it's a rhd. I used a voltmeter on the 3 wire plug (green,white and black) and when I turn the key to the on position the green wire has 12.6 volts.

[E30BTR]

So I still can’t solve my issue, I’m trying to crank my engine over and do a compression test but when I go to crank over the car I get nothing. (I don’t have fuel pump, cps, oil pressure sensor and head lights hooked up, the grounds are all hooked up). I tried to trace the wires back with continuity test from the green wire in the first pic to another wire inside the cabin and engine bay but nothing. Also as seen in the first pic I got a continuity reading from the bl/yl wire that goes to/from the starter. The reading came from the bl/yl wire and the coil wires in pic 2 and the ground wires in the third pic, also I got continuity from every fuse, even when I touch the engine or anything metal/ground and in the forth pic from the two connecters( I have no clue what they go to).

[spdracrm3]

Etm ?

do you have the ETM for your car or something close ? if not if not try downloading a few from here http://www.wedophones.com/BMWManualsLead.htm to compare and study wiring diagrams to help you understand how the systems work and so you can check voltages back thru the circuits. page 1240-1 of the 86 325 ETM show the start circuit and a BLK/YLW wire from ignition switch to starter solenoid for starter engagement which you mention do you have 12v on that wire with the key turned to start position? if not you need to test voltage coming into ignition switch (large RED wire at ign switch as seen in diagram)

eyelets in third picture look like ground bundles (most ground wires on BMW's are solid brown) pull the insulation back to check wire colors if they are all brown those need to be attached to chassis or engine to provide grounding ,all kinds of crazy things can/will happen with poor or not connected grounds.

[E30BTR]

I haven't had a chance to work on the car today but the 3rd pic is ground wires( all brown) the grounds were the first thing I did was check the grounds. When I get a chance I will trace the ignition wire back to the starter hopefully tomorrow night. Thank you for the diagrams.