Technical Wiring issue

[Auldian]

HELP!! I’ve been trying to wire up a Bluetooth reversing camera to my Doblo Maxi 2017 model. I checked the camera was working by hooking it up to the battery. However when I connect the camera/Bluetooth harness to the reversing light live feed from the rear light cluster, the camera can’t pair with the monitor.
Anyone got any suggestions as to what I might be doing wrong. I’m at my wits end.

 

[jackwhoo]

I don't know for your specific vehicle but often on modern vehicles the positive feed to rear lights is not a constant voltage but rather pulsed supply. Reversing cameras etc often won't work on a pulsed electrical supply .

 

[Auldian]

I don't know for your specific vehicle but often on modern vehicles the positive feed to rear lights is not a constant voltage but rather pulsed supply. Reversing cameras etc often won't work on a pulsed electrical supply .

That makes sense as when I put multimeter across the live and the earth take offs at the cluster end I don’t get 12V reading but only .56V. This puzzles me as I can't understand how this sort of voltage can power a 12V21W bulb.