Wiring Appendix IV The Steering Column Switches
The most complicated part of the wiring must be the Steering Column Switch Unit, as there are three versions, (83 BG, 87 BG & 90 BG) with 30 wires to connect. There are seven plugs. Horn, Ignition, Lighting, Hazard, Wash/Wipe Front, Rear and Main Beam. Some versions do not have the Hazard Unit fitted or the Rear Wash/Wipe.(If you have details of the 83 BG pin out please send to me and I will include)
Given below is a chart for the 87BG & 90 BG (both the same) units showing the Switch Function and Location, Sierra (Haynes) Wire Colours, Pin Numbers and the PWS Loom Colours. When joining the Sierra unit to the PWS loom stagger the joints to avoid 30 termination's at one point. Using the crimps supplied or Butt crimps from JST (RS Components) terminate the loom to the unit. This is best done off the car. To read the pins correctly, view the column unit from the front of the car and rotate the unit 90 degs anti-clockwise. The socket location is given before rotation. You are viewing the pins from the BACK or PIN SIDE of the plug. All pins are read Left to Right and the pin idents should read the correct way up after rotation. The idents are moulded into the sockets and are very hard to see.
Colours as per Haynes. B=Blue, Bk=Black, Bn=Brown, Gn=Green, R=Red, Rs=Pink, S=Grey, V=Violet, P=Purple, W=White, Y=Yellow.
Top centre. Horn 2 wire plug on leads.
|
Sierra Colour |
Bn/W |
Br |
|
Pin Number |
Plug |
Plug |
|
PWS Colour |
R/Y |
Br |
Two flat pins Upper Left. Dipped Headlight Switch.
|
Sierra Colour |
Not used |
Brown |
|
Pin Number |
55
|
31 |
|
PWS Colour |
- |
- |
Right Socket Outer Row. Indicators/Hazard Warning.
|
Sierra Colour |
Bk/W |
Bk/W |
- |
- |
|
Pin Number |
L |
49a |
No pin |
No pin |
|
PWS Colour |
Bk/W |
W/Bk |
- |
- |
Right Socket Middle Row. Indicators/Hazard Warning.
|
Sierra Colour |
Bk |
Bk/Gn |
R |
- |
Bk/R |
|
Pin Number |
54 |
R |
H30 |
No pin |
49 |
|
PWS Colour |
Bk/R |
Bk/Gn |
R/B |
- |
Bk/Y |
Right Socket Inner Row. Dip Switch. The housings are polarized but the plugs are not. ie: they are interchangeable. Watch the colours on assembly.
|
Sierra Colour |
Bn |
Bn/Y |
Bn/W |
Bn/Bk |
|
Pin Number |
31 or 15 |
56a |
56b |
56 |
|
PWS Colour |
Bn |
Bn/W |
Bn/Y |
Bn/Bk |
Left Socket Inner Row. Wiper Switch. The housings are polarized but the plugs are not. ie: they are interchangeable. Watch the colours on assembly.
|
Sierra Colour |
Bn/W |
Gn |
Bk/V(2) |
R |
|
Pin Number |
31b1 |
53 |
54 |
53b |
|
PWS Colour |
Bn/W |
Gn |
Bk/P |
R |
Left Socket Middle Row. Lighting Switch.
|
Sierra Colour |
Bn/Y |
Bk/Y |
R |
Bk/V |
|
Pin Number |
31b2 |
W |
30 |
53a |
|
PWS Colour |
Bn/Y |
** |
R |
Not used |
** Earth point for Screen Washer Motor
Left Socket Outer Row. Lighting Switch.
|
Sierra Colour |
Bk/Bn(2) |
Bk/Gn |
S |
Bk |
|
Pin Number |
56 |
53-2 |
58 |
53c |
|
PWS Colour |
Bn/Bk |
Bk/Gn |
S |
Bk/B |
Bottom Right Ignition Switch. (Four heavy duty wires) The Yellow is an un-switched live output. Not included in the PWS loom.
Pin 15 is the +ve supply for the Ignition Coil (changes to Black on its way to the coil), and may also go to an Engine Managemant Relay.
|
Sierra Colour |
Red |
Yellow |
Black/Yellow |
Black/Blue |
|
Pin Number |
30 |
R |
15 |
50 |
|
PWS Colour |
Red |
Not used |
Black/Yellow |
Black/Blue |
|
Function |
Battery Positive |
Radio etc. |
Pin 7 Instr & Coil. |
Starter Solenoid |
© Colin Usher 2007