Hmmm...on my 07 RT that plug, assuming you are talking about the one on the forward left front side from your seat, does run through canbus. No inline fuse, just goes into the harness.

Are you the first owner? I ask that because it is possible that someone wanted to run heated clothing off that plug, which I don't believe it will support. The alternative is to connect direct to the battery. Somebody may have rerouted it for that purpose. Or maybe its just different on a '09.

 

The factory socket on the RT's will support a heated jacket plus gloves (about 8 amps). What size fuse was it that was blown? As a replacement I'd probably use a 10 or 15.

And I agree that the OP's wiring is not original, but it is fairly common and is usable with a good non-BMW charger.

 

Removed the tupperware on my 09 RT to see if I could find out why the 12volt plug in wasn't working. Thought I had read where it was wired thru the CANBUS so was hoping it was something simple like being unplugged.
Well come to find out it's wired direct to the battery and protected by a European type inline fuse. Traced the wires under the fuel cell to the battery and fuse is but a few inches from the battery. Fuse was burnt out and a trip to parts store in hope they had some which they did It might be worth a look next time you're under the hood to see if your RT is wired likewise as you should be able to use this plugin to charge the battery.

if you ordered it after the bike was built they attached it to the battery. My guess that was the case. Mine came from the factory already installed and was in the canbuss wiring harness.

 

I also think that BMW wires the accessory sockets so they are CAN-bus activated.
This has a few disadvantages, such as not being able to use a "standard" charger.
Therefore, these sockets (usually the one in the rear, placed afterwards) is wired
directly to the battery. As every advantage has a disadvantage, this strategy means
the second socket is Always Powered
Gaby

 

To answer a couple of questions, I am the original owner and I had an additional port added when I bought the bike. Wasn't there when they installed the port but I figured it would be the rear port. The fuse has the number 16 stamped in the plastic. I don't know if the Germans use the amp measure and this means 16 amp which is more than the manual calls for but that's what came out of the inline holder. Funny thing is the rear socket appears to wired thru the canbus as I traced that wiring to a juction box and it had no direct connection to the battery. Could be the rear socket was factory and the front one was dealer installed ?

 

The socket in question was without a doubt added post-factory.

Very strange, but in the end not a problem and may be better.

I added the rear socket and went direct to battery via fuse but with a junction in the wiring to give access under the seat for powering my tire pump. My stock front/left socket is CANBUS.

 

Current and voltage are real international engineering units, no difference between metric and imperial units, Amps and Volts on both sides of the ocean :thumb:
A fuse marked "16" is indeed 16 Amps. Since the possible current drain via the socket is variable, the value of the fuse was probably chosen as a short circuit
protection only.
Gaby

 

I know I'm wasting my time but that's Ok. The power socket as installed stock is NOT controlled by CanBus it is controlled by the ZFE and Canbus couldn't care less.

Aftermarket lights can say CanBus compatible, I believe the reason for this is a model that uses CanBus uses the ZFE (central electronics control unit) causing the confusion.

If you have an inline fuse, before upping the fuse amp rating be sure the wire gauge can support it. As a basic rule of thumb you don't want to pull more than 90% of the fuse rating
(15 amp fuse = 13.5 amp draw, etc) Some say no more than 80% but at least allow a buffer.