84 318 -> OBD 1 M52 swap, wiring help needed

[2mAn]

Did some searching around and I am hoping to get a few things cleared up. My car is an 84 318 and Im using a 93 E34 Wiring Harness for my OBD1 converted M52. Ive searched a lot, but I dont think Ive got it completely figured out yet. I am getting close

I've copied wiring arrangement and the wires that DONT match my harness are in bold.

84 325 pin arrangement on 19 pin rectangular C101
Pin#---{Color}---Destination/ Purpose
1---{Blue}---Alternator Charging
2---{Blue/ Yellow}---Oil Level Sensor (my 84 doesnt have this wire in the connector???)
3------ Not used
4---{Brown/ Violet}---Coolant Temperature Sender
5------Not used
6---{Green/ Yellow}---Oxygen Sensor Relay
7---{Red/ Violet (Green/Violet on mine)}---Fuel Pump
8---{Black/ Yellow}---Starter
9------Not used
10---{Green}---Ignition Switch
11-14------Not used
15---{ Violet/ Green }----Oil Level Sensor (my 84 doesnt have this wire in the connector???)
16---{Brown/ Green}---Oil Pressure Switch
17---{Blue/ White}---Diagnostic connector pin #7 Service Reset
18------Not used
19------Not used
For Tach Signal---Pin 7 on C-1 blue 25 pin connector on instrument panel



93 525i pin arrangement on 25 pin round X20
Pin#---{Color}---Destination/ Purpose
1---{Blue/ White}---Oil Level Sensor (static)
2---{Blue/ Green}----Oil Level Sensor (dynamic)
3---{Red/ White}---ABS/ Slip Control Module
4---{Black/ Blue}---Transmission Control Module
5---{Black/ Gray}---Aux Fan
6---{Violet/ Gray}---?????
7---{Black/ Violet}---SI Reset
8---{Green}---Check Engine Light
9---{Green/ White}---Oil Temp Sensor
10---{Brown/ Black}----Instrument Cluster/ Check Control
11---{Brown/ Green}---Engine Coolant Temp Sensor
12---{Brown/ Violet}---Engine Coolant Temp Sensor
13---{Green/ Violet}---Fuel Pump Relay
14---{Black/ White}---Speed Sensor
15---{Black/ Green}---Starter
16---{White/ Green}---Data Link
17---{White/ Violet}---Data Link
18---{Black/ Green}---Voltage during startup
19---{White/ Green}---Diagnostic Plug
20---{Black}---Engine Speed- Tach
21---{Green}---Ignition Switch
22------????????
23---{Brown/ Green}---Oil Light
24---{White/ Black}---Fuel Rate output
25---{Blue}---Alternator



Heres what my adaption will look like (probably using an old Rectangular C101 engine side plug)

C101 Pin # & Color___Job___X20 Pin # & Color
1__Blue_________Alternator Charging______25_Blue
2__Blue/ Violet___Oil Level Sensor (static)__1__Blue/ White***
3_______________Not used___________
4_Brown/ Violet__Coolant Temp Sensor____12_Brown/ Violet
5______________Not used____________
6_Green/ Yellow__Oxygen Sensor_________?????????
7_Green/ Violet___Fuel Pump_____________13_Green/ Violet
8_Black/ Yellow___Starter_______________18_Black/ Green
9_______________Not used_____________
10_Green________Ignition_______________21_Green
11-14___________Not used______________
15_Violet/ Green___Oil Level Sensor_______2__Blue/ Green ***
16_Brown/ Green__Oil Pressure Switch_____23_Brown/ Green
17_Blue/ White___Diag. Connector pin#7___7__Black/ Violet
18 & 19_________Not used_______________

C104 Pin # & Color___Job___X20 Pin # & Color
1__Black_______Engine Speed Input (Tach)__14_Black/ White
2__Green_______??????????????
3__Yellow +???___Econo Gauge____________24_White/ Black

[shiboujin]

I have a premade harness from a parts car that I had a while ago. I can sell you that one. No idea what it's worth but I know the guy that did the wiring and trust him. Never saw that parts car run though...

[2mAn]

Is it for an 84?

[shiboujin]

Square plug. Not the normal C101 *shrugs*

[2mAn]

rectangular C101?

[shiboujin]

yea. I think it's called something other than a C101 in early eta cars. But yea, rectangle into the stock M50 harness X20.

[2mAn]

would prefer to do the wiring myself, but shoot me a PM about it. Anyone have some info to help out?

[328ijunkie]

There's a reason I charge more for the m10 cars lol. Pita. :P

[2mAn]

bump. mostly curious what I need to do for my oil level sensors since my M10 car didnt have the wiring going through the C101. I havent traced the wiring on my current motor to see where it goes, but I have a feeling these go through the C104, but havent found the info on the wiring diagram... getting close though

[Jean]

It's still a c101, you just run the mpg/tach/check engine lights to the car and ignore the oil level sensor wires unless you want to add a check panel..... Cut the rectangular c101 off, install round one to match the engine harness, run the extra wires to inside the car/dash. Done.