So I'm trying to avoid having to run a #10 wire for 15A DC (+) from my boot in back up to the battery that would power a trailer light module from Tekonsha.

They say it's best to do this so module's powered 24/7/365. I can understand that, particularly if module needs to be "programmed" to interpret tail and brake light wiring signals coming in from the sensors the module takes its info from to then power the lights on trailer downstream.

BUT routing anything like a #10 wire so it's both protected and also doesn't disturb any of the factory wiring harness is a major PITA.

So if I can use the 12V (+) from the lighter socket in the boot, I think that would be acceptable. If I need to 'program' the trailer light module every time I hook it up that's less of a problem, at least until I can get a handle on where I'd need to route a direct-power wire from battery.

SO can anyone reading this thread interpret which symbol on my '13 Clubman's fuse panel might be for that lighter socket in back?





Or what the one for the 20A fuse @ F44 might be for? Can-bus electronics are newer than my decades-old brain can fathom.

 

f44 on your chart should be the front 12v
outlet (cig lighter) and the similar outlet
in the boot.

 

Thanks Cristo, I had a hunch that was what it might be for.

Friend sent me this from his Bentley R56 service manual:




But not knowing made me ask.

If one looks at it as a "charging socket" as opposed to a cigarette / cigar lighter, then the symbol makes some sense.

That it's nearly as hard to take power from the fuse panel as from the battery has me thinking I'd be better off running that #10 wire supplied with the Tekonsha module as recommended. It's not that much farther to the battery now, is it?

Now I need to find where to get an idea of where I can pass a wire through the firewall someplace accessible... and find some key that explains what the wiring color codes are....

 

BMW WIRING COLOR CODES
Code German English
BL blau blue
BR braun brown
GE gelb yellow
GR grau gray
GN grun green
RT rot red
SW schwartz black
WS weiss white
VI violett violet