Wiring Hook ups

[B3M2W5]

Ok i am starting to put the wiring harness i have bought on the engine.
The engine is still on the stand and i am just mocking things up.
My question is how do i find out what conector goes on what plug??
It seems to me like there is more on the harness then there is on the motor.
Can any one help me out here its starting to get cold and all i have is a rocket so i need to get this Puppy in the car soon.

[Mike B.]

Electronic Troubleshooting Manual (ETM) / Bentley Manual

Locate the systems, identify the wire colors and match that to your harness. Tedious and time consuming, but it is the best way to learn the systems and how your car is wired up.

If you get stuck on a certain connector, post a picture and the wire colors and we can help you make an identification.

What year is the engine? If your email can handle large file sizes (>10MB), I can send the correct ETM file to you.

[BigD]

Find the right ETM for your wiring harness, find the pin description for the Motronic connector, go through it and just use a multi-meter (preferably one with a manual mode for resistance testing, so it beeps on short circuit) and common sense. IE if you're trying to figure out the connector for the coolant sensors, it's probably not the one bundled with the MAF or O2, it's probably one of the 3 connectors by the coolant sensors, and since the sensor is a 2 prong, there's no sense checking the 3 prong connectors... I was also initially dreading having to fish for wire colors but you don't have to do that, it's very easy and takes a few mins. I've never done this swap before and I had my harness on in like 10 min.

[B3M2W5]

Ok i should have gone into a little more detail, I have an 87 325e, and i am putting an M50 out of a Jan of 94 E36 325. I have had to buy all of the OBDI stuff ex. (Mani, Harness, ECU) and what not. I am now getting down to the small parts and Wiring, really im not even to cutting and splicing yet just hooking up the harness is what im stuck on so if any one could help me out i would be very greatfull
I am sorry to be a nusence i know this is probly listed in here some where but i really simply dont have the time to look. I have Auto Tech school from about 8 to at least 3 every day of the week plus 2 jobs. Im 19 and only have a Rocket to drive and if any one knows what its like in Iowa it can be 45 deg. on day and 70 the next. Its winding down and starting to get cold in the mornings so if any one knows of or could post some links as to where i could find these diagrams i would really apreciate it.
On top of that, i think i did a booboo and threw away my E30 engine harness and from what i thought i read it sounds like i needed it to cut the end off and wire that to my E36 harness. Is there a way to just wire the body harnes to the Engine i can Solder and what not but was wondering if that would cause problems.

[B3M2W5]

Electronic Troubleshooting Manual (ETM) / Bentley Manual

Locate the systems, identify the wire colors and match that to your harness. Tedious and time consuming, but it is the best way to learn the systems and how your car is wired up.

If you get stuck on a certain connector, post a picture and the wire colors and we can help you make an identification.

What year is the engine? If your email can handle large file sizes (>10MB), I can send the correct ETM file to you.

Im not sure what size my email is but as to my last post its an M50 out of a 94 325 so if you could send any diagrams to either of my email ill see what i can get and it would be very appreciated.
I have 2 right now
325kid@gmail.com
Cidvicious99@aol.com (From around middle school kinda childish)

[Mike B.]

I sent the file...

You don't need your E30 engine side harness. Just buy the E30 engine side C101connector and pins and make your own. You can find the part numbers on Realoem.com, or they may be around somewhere if you do a search.

Don't forget to keep your E30 coolant temp sensor... You'll need it for the temp gauge in your cluster to read correctly.

[B3M2W5]

I sent the file...

You don't need your E30 engine side harness. Just buy the E30 engine side C101connector and pins and make your own. You can find the part numbers on Realoem.com, or they may be around somewhere if you do a search.

Don't forget to keep your E30 coolant temp sensor... You'll need it for the temp gauge in your cluster to read correctly.

Yea i kept the sensor thats the one with only one prong right. So i was wondering what hooks to that on the harness there appers to be only one conector on the harness with one prong inlet and there are 2 conectors on the motor now.?
Thanks for the file

[Mike B.]

Yep, the one with one prong.

Without knowing the wire colors, I have no idea on the connector. Any answer would just be a guess.

[bimerok]

The plug on the harness that hooks up to temp. sensor will have 2 prongs! Original m/s50 temp. sensor had 2 prongs so will the connector on the harness.

I can tell you that the one pin that is used after installing e30 sensor is going to pin 12 on x20 connector.

[B3M2W5]

Ok i got a friend over that has a 94 325 also, but i kinda forgot that the harness is either from a 93 or a 95 im not sure but it might be a 94 harness. I dont remeber i have to one if for a man. the other is for an Auto and im not sure what one is what year. Any ways i start pulling some things on his car and then looking for them
I found the Throtle body, the coolent sensors in the head too.
I am having some trouble reading this Adobe file of the ETM im not ure what i am looking at when i see this. Is there any one that can help me if i can the number of prongs and the wire colors to them or explain how to read this Adobe file.

[BigD]

Guy I already told you, forget about the wire colors, stop overcomplicating it. There's a 2 or 3 page list of the Motronic connector pin functions. Find the sensors in the list, then one at a time with multimeter, match them up to the plugs (well some you can figure out from common sense). Takes 10-15 mins.