Wiring Loom

GreatOldOne · #1 8th January 2006, 13:24

Guys,

I've started stripping my beemer, and everything has been going ok so far. Then I started to unplug electrical connections - labeling as I go - in the engine bay ready for hoiking out the engine. One of the steps in the Bentley manual is removing the conections to the ECU under the glove box. All very straight forward - remove two connectors and push the cable through the grommet in the firewall. Except that wiring in my beemer looks completely different! there's the large plastic connector entering the front of the ECU, but then it all gets complicated. There's a ton more connectors in there and they all look authentic BMW (i.e nobody's mucked about with it)

So, the questions are these - Just how much of the loom do I need? As there seems to be stuff in there that's not in the Bentley, what did you guys take out? The Marlin parts list just says the engine wiring harness - but what does that constitute exactly? Help!

MartinClan · #2 8th January 2006, 16:17

Did your donor have cruise control by any chance. I believe the controller for this is mounted near the ECU and will add extra wiring. My engine loom came out pretty much as in the Bently manual except that there were a couple of small extra connectors next to the ECU one. that didn't sonnect to anything.

There is a good (Russian!) website that has all the wiring coulrs for the engine loom http://www.autolib.diakom.ru:8001/CAR/BMW/ this migt help you.

Are the other wires you have all tied up in the engine loom or are they just running thru' the same hole in the bulkhead?

GreatOldOne · #3 8th January 2006, 17:15

I don't think the car has cruise - I havent seen anything on the dash / column to set it... However, I could be wrong so I'll double check.

They extra connectors seem to be part if the loom, which consists of - two thick bundles of cables, one which has the large white ecu connector. They (the bundles) both go through the bulkhead into the engine bay. I'll try and take some pics of the rats nest tommorow night and post them up.

GreatOldOne · #4 9th January 2006, 17:33

Right, the car definiely does not have cruise control.

Anyway, here's the pics. Those of a nervous disposition should look away now!

the main ecu connector is on the bundle topmost and to the right of the picture. it has has two extra cables entering it, one with what looks like a relay on the end of it, and the other diving off into the dash. There's also a brown earth.

The connector and relay on the end of the bundle mentioned above.

There's another bundle in the centre of the pic that was connected via a quick connector. I've labled both ends of it and disconnected it

There's some other connectors in there - individual connectors going into a couple of multi contact block. These where attached to the bulkhead by a plastic frame that came away due to the rust!

MartinClan · #5 9th January 2006, 19:50

Strange - a few idea's

1- The connector looks like the one for the ABS - not the ECU. On my loom the ECU connector is blck and has three rows of pins - the ABS one is white and has two rows of pins.

2. Some of the wiring looks like the main wiring loom that goes to the fusebox - difficult to tell in picture - sorry.

3. My loom

Assuming I have made the image appear...
1 = ecu connector
2 = connector to main loom (just out of sight - round multipin connector)
3 = lambda sensor connector
4 = coil

Suggest you carry on and try to extract the engine loom and see what it looks like then![img][/img]

MartinClan · #6 9th January 2006, 19:58

Picture of abs controller plug

GreatOldOne · #7 10th January 2006, 08:10

Aha! so the silver box that I spent an hour extracting on Sunday is the ABS then... That would explain things...

So whereabouts was your ECU located Martin? I can't see anything else under their that looks like a control module. Is it on the right hand side under the instrument binacle? I ask because I'm getting the feeling that all of the pics in the Bently need flipping L-R due to the Yank factor.

Thanks for the pics. Very helpful mate. Oh, by the way - Your loom looks very neat. Care to do mine?

Patrick · #8 10th January 2006, 09:57

The ECU is where your knees are on the driver side, the ABS one is behind where the glove box is.

GreatOldOne · #9 10th January 2006, 10:16

Thanks guys.

GreatOldOne · #10 11th January 2006, 12:05

I've now got the ECU out! The wiring harness has been pushed through the bulkhead into the engine bay. The funny thing is that it has exactly the same type of connector as the ABS did...

Thanks again.

MartinClan · #11 12th January 2006, 19:38

Glad you got it sorted. Your loom will look the same as mine one you have cleaned it and removed the bits you don't need!

It's the main wiring loom that's a bit more tricky!

Cheers

Robin

GreatOldOne · #12 16th January 2006, 07:58

Well, it's finally out! I managed to label and extricate all of the cables from the engine at the weekend, and managed to drain the cooling system and remove the radiator. That and destroying Bristol in the Challenge Cup on Saturday made for a very fullfilling weekend!

Another question arises though... Now that I've got the dame thing out, I don't seem to have a lead going to the lamda sensor on my loom. I've got all of the other leads for stuff like oil pressure & level, TDC, speed, water temp, reference and of course all the injectors - but nothing for that.

The other oddity is that the auxillary relay panel that used to sit on near the right hand suspension tower only had two relays - all of the pics in the bently manual show three of them. It looks as if the car has only ever had two, as there's only two leads coming from the loom to the panel - and the car fired up and ran OK, so it's obviously not missing it. I'm just a little puzzled why it's not there.

Patrick · #13 16th January 2006, 08:37

Mine only had two relays as well. There was a good reason for this, but don't remember right now. When I do I will let you know!

GreatOldOne · #14 16th January 2006, 08:59

Ta. All becomes clear on the Lamda sensor as well... Helps if you read all the threads on the forum, eh?

GreatOldOne · #15 16th January 2006, 12:44

And the Mystery of the Missing Relay can be put to bed as well.

According to this thread on the Roadfly forums, the third relay is for the Oxygen / Lambda sensor. So if you don't have a lambda sensor, you're not going to have the relay.

I assume the Bently manual doesn't mention this, as all Yank e30's must have been fitted with Cats and O2 sensors, thanks to all the treehugging Californians.

Patrick · #16 16th January 2006, 12:45

Excellent