Voltage Sensing in CANBUS fitted vehicles

Thread Starter

Ask Itee

Joined Feb 6, 2019
I had some driving lights fitted to my Motorcycle by the dealership. My expectation was that he would fit a relay powered from the battery, tap into the high beam circuit to get a "signal" to activate the relay when the high beam was activated. When I collected the MC he explained that due to the sensitivity of the CANBUS, it was not recommended to tap into the high beam circuit as the CANBUS is will have a conniption.

I have witnessed changing headlight globes from Halogen to LED causing the CANBUS to shut down the headlight circuit, so it sounded reasonable.

It got me thinking. I worked at a 2000MW Coal Fired Power Station for 19 yrs and recall a device called a Tong Ammeter which sensed the presence of electricty in a cable into say a motor or switchboard.

Is there a small electronic device that instead if tapping into say the 12v High Beam positive via a scotch lock or other physical connection, wraps around the wire and senses the high beam circuit is active that would send the signal to the relay to activate the relay? Or am I dreaming?