Powering a dashcam off the sunroof wiring on a MK4 Jetta

There are 3 wires of importance going to the sunroof: brown is ground, red is 12V, and yellow is switched (12V when the car is on, 0V when it's off). Because the yellow wire doesn't offer enough current to run a charger, I use it to trigger a 12V relay instead (yellow to the relay's positive coil wire, brown to the negative coil wire).

The charger has only two wires: ground and 12V. I connect the ground of the charger to brown, and and the 12V wire to the normally-open contact on the relay. The other side of the normally-open contact I connect to the red 12V wire on the sunroof.

When the car is on, the yellow wire triggers the relay, which closes the contact, effectively connecting the red (always on) wire to the charger. If you need help, ask me in the comments.

Видео Powering a dashcam off the sunroof wiring on a MK4 Jetta канала Adam Davenport