Fog light button wiring

[Dionk]

Any advice on wiring an e21 fog light switch? I will be using a relay - i assume +31 post is positive in but then there are two “S’s”  one I’m thinking is the remote wire to the relay and the other a ground? 

[Henning]

17 minutes ago, Dionk said:

Any advice on wiring an e21 fog light switch? I will be using a relay - i assume +31 post is positive in but then there are two “S’s”  one I’m thinking is the remote wire to the relay and the other a ground? 

 

 

Be careful, Dionk. The stamping is confusing.

"31" is ground in any german car and is meant to mark the terminal in the center, not the one at 1 o'clock. It is needed as ground for the integrated little light bulb in the switch's yellow knob. Never mix up + and 31 !

The one at 1 o'clock (+) is power from a fuse or from a driving / parking light signal. In 71 and later cars there are connectors for additional electrics; check the diagrams.

"S" is Scheinwerfer (shine launcher) but you better run it to the control circuit in your relay (85).

 

hen

 

Edited April 18, 2020 by Henning

[John76]

I used a lighted switch from a 530i, and wired it this way. should be the same with your switch.

 

[Dionk]

2 hours ago, John76 said:

used a lighted switch from a 530i, and wired it this way. should be the same with your switch.

Wow - I found the original post of this and was looking at it an hour ago! Thank you

 

9 hours ago, Henning said:

Be careful,

Thank you

[John76]

As Hen said, the center tab is #31 GROUND.

The "+" tab is for the 12V from the #9 fuse terminal, which will only turn on the fog lights on LOW BEAM.

The "S" tab is the signal to the #86 relay terminal.

Always a good idea to bench-test your switch before installing.....we have heard way too many tales of smoking wires lately.