Originally Posted by bradtopp
Could you please explain why it is a concern? I'd be much more concerned wiring directly to the battery. I've learned over the years to never wire directly to the battery without a relay. The GPS connection is CAN bus controlled and prevents battery drainage. The cigarette lighter type charger I had wired to the same GPS harness had no problems for the past year (BMW GPS harness wired to cigarette adapter to car iPhone USB charger).
I'll give wiring directly a shot but I know with 100% certainty this will make no difference.
Many posts here in the GSpot talk about how the Canbus detects devices attached to it, like the BMW battery tender. It also has a virtual fuse. It can act differently from a standard battery connection. Many companies like Kisantech have had to redesign their headlight modulators to work with the canbus.
I'm asking you to connect it directly to the battery to diagnose your problem.. I'm just trying to eliminate possible issues. If there is no problem with the direct battery hookup then we know that the BMW GPS connector could be causing some weird electrical problem. If you experience the same non-charging state from direct to battery, then we can blame the USB charger.
If it's the USB charger I'll send you a new one, even if you hacked it up.