Fog light function US 230SL

[lagolag]

I did some work on my headlights and checked all bulbs that was fully working but the Fog light wouldn’t be lit (bulbs are OK) when I pulled the light switch I checked the Forum and found that US version might not have the “Stand Licht” (turning light switch to the left) and the Fog connected. My car has function when turning the switch to the left and the I noticed that the grey/green/yellow is not connected it is isolated to the harness, thought that I could connect the G/G/Y to N, but noticed that N and 57 was occupied already by two black cables in a harness that follows the main harness trough the fire wall and was connected to fuse holder beside the clutch fluid bottle. When I test the connection of the twin black cables, it is a closed loop between N and 57 through the fuse. I disconnected the black once and connected the G/G/Y to N and now I have a working Fog light.
My bumpers have cover plugs where the Aux light can be fitted, this can answer why there is a harness with the two cables that is unused and it was connected to N and 57.
While I tried to get the fog light to work, I also noticed a brown cable hanging loose, see picture, from the light harness, I can’t find any information where it should be connected, I need help on this, I know that brown is earth but do I dare to connect it to no 57 that is not used according to the electrical chart?

My car was FC November 24, 1966

[lpeterssen]

Dear friend

Let me look at wiring harness diagrams and will come with an answer right away.

Best regards
Leo

[lpeterssen]

Dear friend

You did Almost right.

The grey/yellow/green cable or Grau/gelb/gruen in German cable certainly goes to one of the available “N” post on the main light switch, to let the function fog lights to work.  I refer to the fog light bulbs “E” on diagram attached which are integrated to the main front light assemblies.

That function uses that grey/yellow/green cable as the feed hot line which comes from fuse no.8, and passes it to the grey/green cables to feed integrated headlight assemblies fog lights “E”.  See diagram attached.

On the other hand you can install a set of auxiliary round nebelscheinwerfer (auxiliary front fog lights) which are usually installed next to main headlamp assemblies and those are driven with an auxiliary wiring harness, which needs a power from main light switch to be activated.

Those two black cables are, as you said, the feed lines to the auxiliary fuse box you found on the engine bay next to fender.

There are many possible ways to connect that auxiliar fog lamps harness. 

THE HANGING BROWN CABLE SHOULD ONLY CONNECTED TO GROUND, NOT TO PORT 57

Manual says that port 57 is not in use because that port is for connecting auxiliary fog lights.

The connections should be this way:

1. Two black cables which end on the auxiliary double fuse box found on engine compartment, go to port 57 main light switch.
2. Ground cable brown hanging, to any suitable ground post. Screw it to any metal part that has ground.
3. Grey/yellow/green as already done go to port “N”

I guess that that hanging ground belongs to a relay installed somewhere, you have to dig further, and I also guess that it relates to an auxiliary relay used to drive those auxiliary fog lights.

A relay normally has 4 post which connect this way

1. Port 85 of the coil goes to ground, it may be that hanging brown cable you have
2. Port 86 of the coil goes to the 12V trigger line, I mean the signal which makes the relay to close its main circuit and let the current pass trough
3. Port 30 goes to the hot side, for example that could go to the output of the fuse holder already mentioned.
4. Port 87 is the switched side which goes to the accessory you are switching on and off, in this case to the aux fog lights.

On main light switch the port 57 is energized only when the switch has passed clockwise to position 1 or 2 and you pull it. So when light switch is pulled out, that port has energy.

You have to dig further and see if there is any other relay there

Best regards
Leo

[lpeterssen]

Dear friend

That hanging brown cable, together with the gray/blue that is shown on your main light switch loom picture belongs to an ILLUMINATION  CIRCUIT.

So that is for bringing light to the Speedometer housing in the back.

Forget about my initial idea of a RELAY somewhere…..

And definitely the two black large cables go to port 57 on main light switch.

From the fuse box in the engine bay you may feed in the future a pair of auxiliary fog light assemblies.

Best regards
Leo

[lagolag]

Thanks a lot Leo for great support and rapid answers!

The grey/blue in the picture is the Tacho light, everyting lights up as it should without the brown connected to earth.
I doubt that it was connected on the pin where the curled nut and bracket holds the Tacho fixed to the dash.
I'll figure  it out when to ground it when I put all together again.
I did look carefully on the chart before I raised the issue here and in the chart I can see a short black lead on 57 but there is nothing mentioned there.
When it comes to brown earth are most of the earth points shown in the chart but not the one for the light harness, that's strange I would say.

Great thanks again
Best regards
Lars Lagstrom

[lpeterssen]

Dear Lars

If the brown is long enough to bring ground to the tacho housing ground it.

The terminal 57 on main light switch shown on wiring diagram connected to a small black lead maybe means that optional auxiliary fog lamps have a black 12v fed cable.

But for sure that terminal 57 according to many literature is for auxiliary fog lamps apart to the ones included inside the main headlight assemblies fed with grey/green cables.

Best regards
Leo

[lagolag]

Dear Leo,

Among saved files I fond a tutorial on how to remove the instruments, there I found this picture and this indicates that the Brown most likely is attached to the Tacho fixation pin screw by the curled nut.

So now foglight connection and earth of the light harness is sorted by joint forces, Thank you.

Best Regards
Lars