Hey R3V-
I just added these wiring bits to my 318 when doing a chassis harness and figured I'd offer a reference on what wires make up a lot of the sub harnesses/where they go. This isn't a how-to install these components in your car, just some helpful wiring input that I think will save someone from digging through ETMs to find out where wires go.
Cruise: To add cruise, there is a writeup jakeb did years ago, here is a link to his photos: http://www.theguestroom.net/car/318cruise/
-Blue plug that looks like a cluster plug. This plugs into the cruise computer, which sits above the glove box.
-Single Blue/Yellow stripe wire with single black plug. This plugs into the green coding plug on the back of the speedo, in the top right port. (Your 318 doesn't have this coding plug, so that needs to be sourced from a car that had cruise).
-Two wire plug (Purple/white stripe and Green/red stripe) - There is normally accessory power for most E30s ran in the chassis harness already, but not on the late 318. This is plug is where the cruise gets power and brake switch reference (to turn cruise off when you hit the brakes). This plug needs to be cut off and joined with the brake light switch under the dash. See Jake's photos above for that reference.
-Single blue/red stripe - this is for auto cars only, and if left unused gets wrapped up in the harness
-7 wire black plug - to actuator (actuator wiring runs inside the car and gets plugged in under the dash)
-5 wire clear plug - to cruise stalk
-2 wire clutch switch - this can be added if you have a clutch switch on your car, the 318 does not, so it can just be wrapped up and not used.
-Ground wire - grounded to grounding point to the upper left of the steering column
4ch Radio Harness w/ Premium Sound
-4 wire plug to junction box - only one place this will fit, and it's the same place as the harness that you're taking out
-Red/black stripe wire that Ys off - Male plug goes to power junction, right below the connector I mentioned above. The female red/black stripe runs to the outside-the-car OBC harness double red/white stripe connector.
-To add tweeters, simple unwrap the blue plug that is in your chassis harness by each front footwell speaker, and plug the blue plug from radio harness into blue plug by front footwell speaker.
-The speaker wiring is self explanatory, as is the amp plug. There is a ground for the amp under the driver side of the rear seat.
13 Button OBC Harness (INTERIOR SIDE)
-Green connector that plugs into 13 button OBC (duh)
-Yellow connector that plugs into cluster (duh)
-3 wire black connector plugs into under dash door chime/gong (p/n 1376047) - these wires are red/white stripe, brown/blue stripe, and brown.
-Single black wire w/ blue plug runs to the 13 button OBC specific turn signal stalk (that your car doesn't come with)
-3 wire green connector plugs into the OBC computer (that your car doesn't come with) - these wires are red/white stripe, brown/blue stripe, and brown/yellow stripe
-2 wire white connector plugs into engine bay side of the 13 button OBC harness, and runs to the ambient temp sensor up under by the drivers side horn - these wires are blue and brown
13 Button OBC Harness (ENGINE BAY SIDE)
Under Dash
-Male 2 wire plug - green/red stripe and solid green wire- this plugs into a female 2 wire plug harness (2 solid green wires) wrapped up in the main chassis loom. It has a redundant loop plugged into it stock on the 318 that will be removed and tossed aside when you plug this male 2 wire plug into it.
-Male 2 wire single pin plug - two red/white stripe wires - this plugs into the radio harness' single red/black stripe wire
-Male 2 wire plug - blue/brown - this plugs into the female 2 wire plug from the interior side of the 13 button OBC harness you've fitted above, also with blue/brown wire
-2 brown wires to a ring terminal - you guessed it, ground baby
In engine bay
-2 wire blue connector to OBC horn, up under regular horn, in fog light area (red/white stripe, and brown/yellow stripe wire)
-2 wire black connector to ambient temp sensor - blue and brown wires
-4 wire green connector to OBC computer - brown/yellow stripe, brown, green, green/red stripe
-2 wire clutch? sensor, hidden under fuse box on auto cars. I don't know where this goes, so I just left it under the fuse box. Brown/green stripe and brown wires.
Cruise:
Blue plug to cruise ECU:
Black plug (blue/yellow stripe wire) to top right port of green coding plug on speedo:
This is how I pulled power/signal from the brake switch to the Purple/white stripe and Green/red stripe wires on the cruise harness:
From left to right- Ground, cruise control stalk plug, clutch switch:
And the cruise control actuator plug:
4ch Radio Harness:
This is what the power junction box will look like. 4 wire plug from radio harness only fits in one way. Single wire red/black stripe plug goes right beneath. Top left is the antenna plug off of your antenna harness in case that was removed from your car. This is on the antenna harness, not the radio harness.
This is where the other red/black stripe wire off of the radio harness plugs into the 13 button OBC (engine bay harness) double red/white stripe plug:
Tweeters plugged in:
13 Button OBC - Interior Side
Green plug to OBC:
Yellow plug to Cluster:
3 wire black connector to door gong. The second door gong plug you see comes off of the main chassis harness under the dash. The plug off of the OBC harness contains wires: red/white stripe, brown/blue stripe, and brown/yellow stripe
Blue plug w/black wire runs that runs to 13 button OBC specific turn signal stalk:
Green plug to OBC computer:
Brown/Blue wire plug to engine bay side of 13 button OBC harness (also brown/blue):
13 Button OBC Harness - Engine Bay Side
Under Dash
Two wire plug (green/red stripe and solid green wire) to two wire (solid green wires) off of chassis harness.
The plug I am holding to the left is what you remove to plug in said plug from engine bay side of OBC harness.
Single plug w/ double red/white stripe wires to red/black stripe wire from radio harness:
Plug with blue/brown wires plugs into interior side of 13 button OBC harness, also with blue/brown wires:
Ground:
In Engine Bay
This is the ambient temp sensor and OBC horn, up under the drivers side front of the car, by the horn. Ambient temp plugs into the air vent/duct with sensor, OBC horn plugs into the OBC horn which is up under the regular horn and tucked away. This plug is normally blue, but mine is broken, as I'm sure most are.
Engine bay side of the harness that runs to the OBC computer:
Connector I mentioned above under fuse box:
I just added these wiring bits to my 318 when doing a chassis harness and figured I'd offer a reference on what wires make up a lot of the sub harnesses/where they go. This isn't a how-to install these components in your car, just some helpful wiring input that I think will save someone from digging through ETMs to find out where wires go.
Cruise: To add cruise, there is a writeup jakeb did years ago, here is a link to his photos: http://www.theguestroom.net/car/318cruise/
-Blue plug that looks like a cluster plug. This plugs into the cruise computer, which sits above the glove box.
-Single Blue/Yellow stripe wire with single black plug. This plugs into the green coding plug on the back of the speedo, in the top right port. (Your 318 doesn't have this coding plug, so that needs to be sourced from a car that had cruise).
-Two wire plug (Purple/white stripe and Green/red stripe) - There is normally accessory power for most E30s ran in the chassis harness already, but not on the late 318. This is plug is where the cruise gets power and brake switch reference (to turn cruise off when you hit the brakes). This plug needs to be cut off and joined with the brake light switch under the dash. See Jake's photos above for that reference.
-Single blue/red stripe - this is for auto cars only, and if left unused gets wrapped up in the harness
-7 wire black plug - to actuator (actuator wiring runs inside the car and gets plugged in under the dash)
-5 wire clear plug - to cruise stalk
-2 wire clutch switch - this can be added if you have a clutch switch on your car, the 318 does not, so it can just be wrapped up and not used.
-Ground wire - grounded to grounding point to the upper left of the steering column
4ch Radio Harness w/ Premium Sound
-4 wire plug to junction box - only one place this will fit, and it's the same place as the harness that you're taking out
-Red/black stripe wire that Ys off - Male plug goes to power junction, right below the connector I mentioned above. The female red/black stripe runs to the outside-the-car OBC harness double red/white stripe connector.
-To add tweeters, simple unwrap the blue plug that is in your chassis harness by each front footwell speaker, and plug the blue plug from radio harness into blue plug by front footwell speaker.
-The speaker wiring is self explanatory, as is the amp plug. There is a ground for the amp under the driver side of the rear seat.
13 Button OBC Harness (INTERIOR SIDE)
-Green connector that plugs into 13 button OBC (duh)
-Yellow connector that plugs into cluster (duh)
-3 wire black connector plugs into under dash door chime/gong (p/n 1376047) - these wires are red/white stripe, brown/blue stripe, and brown.
-Single black wire w/ blue plug runs to the 13 button OBC specific turn signal stalk (that your car doesn't come with)
-3 wire green connector plugs into the OBC computer (that your car doesn't come with) - these wires are red/white stripe, brown/blue stripe, and brown/yellow stripe
-2 wire white connector plugs into engine bay side of the 13 button OBC harness, and runs to the ambient temp sensor up under by the drivers side horn - these wires are blue and brown
13 Button OBC Harness (ENGINE BAY SIDE)
Under Dash
-Male 2 wire plug - green/red stripe and solid green wire- this plugs into a female 2 wire plug harness (2 solid green wires) wrapped up in the main chassis loom. It has a redundant loop plugged into it stock on the 318 that will be removed and tossed aside when you plug this male 2 wire plug into it.
-Male 2 wire single pin plug - two red/white stripe wires - this plugs into the radio harness' single red/black stripe wire
-Male 2 wire plug - blue/brown - this plugs into the female 2 wire plug from the interior side of the 13 button OBC harness you've fitted above, also with blue/brown wire
-2 brown wires to a ring terminal - you guessed it, ground baby
In engine bay
-2 wire blue connector to OBC horn, up under regular horn, in fog light area (red/white stripe, and brown/yellow stripe wire)
-2 wire black connector to ambient temp sensor - blue and brown wires
-4 wire green connector to OBC computer - brown/yellow stripe, brown, green, green/red stripe
-2 wire clutch? sensor, hidden under fuse box on auto cars. I don't know where this goes, so I just left it under the fuse box. Brown/green stripe and brown wires.
Cruise:
Blue plug to cruise ECU:
Black plug (blue/yellow stripe wire) to top right port of green coding plug on speedo:
This is how I pulled power/signal from the brake switch to the Purple/white stripe and Green/red stripe wires on the cruise harness:
From left to right- Ground, cruise control stalk plug, clutch switch:
And the cruise control actuator plug:
4ch Radio Harness:
This is what the power junction box will look like. 4 wire plug from radio harness only fits in one way. Single wire red/black stripe plug goes right beneath. Top left is the antenna plug off of your antenna harness in case that was removed from your car. This is on the antenna harness, not the radio harness.
This is where the other red/black stripe wire off of the radio harness plugs into the 13 button OBC (engine bay harness) double red/white stripe plug:
Tweeters plugged in:
13 Button OBC - Interior Side
Green plug to OBC:
Yellow plug to Cluster:
3 wire black connector to door gong. The second door gong plug you see comes off of the main chassis harness under the dash. The plug off of the OBC harness contains wires: red/white stripe, brown/blue stripe, and brown/yellow stripe
Blue plug w/black wire runs that runs to 13 button OBC specific turn signal stalk:
Green plug to OBC computer:
Brown/Blue wire plug to engine bay side of 13 button OBC harness (also brown/blue):
13 Button OBC Harness - Engine Bay Side
Under Dash
Two wire plug (green/red stripe and solid green wire) to two wire (solid green wires) off of chassis harness.
The plug I am holding to the left is what you remove to plug in said plug from engine bay side of OBC harness.
Single plug w/ double red/white stripe wires to red/black stripe wire from radio harness:
Plug with blue/brown wires plugs into interior side of 13 button OBC harness, also with blue/brown wires:
Ground:
In Engine Bay
This is the ambient temp sensor and OBC horn, up under the drivers side front of the car, by the horn. Ambient temp plugs into the air vent/duct with sensor, OBC horn plugs into the OBC horn which is up under the regular horn and tucked away. This plug is normally blue, but mine is broken, as I'm sure most are.
Engine bay side of the harness that runs to the OBC computer:
Connector I mentioned above under fuse box: