heistnorway

Hello

I need to connect onto the high-beam signal to control extra mounted ledbar.

Does anyone have any diagram / overview, or any simple method to find out wich wire carries the 12v signal to the high beams ?

n0v8or

What style of headlamps are fitted on your vehicle?
Single LED
Triple LED (adaptive)
Halogen

heistnorway

Looks like single LED ?
forgot to mention its a 2018 NX300h

n0v8or

You have the single LED headlamps.
Unfortunately, a 12V wire that could be simply connected to an auxiliary high-beam lamp does not exist in this generation of NX. Refer to the attached flow chart and headlamp design illustrations.
The high-beam / low-beam switch does not operate at 12V. It switches a voltage / low current logic signal to ground. This logic level is encoded by the Body Computer ("body ECU") and sent as a data packet to the left headlamp assembly, over the fast digital communications bus (CANbus). The headlamp ECU decodes the data packet and operates a solenoid within the headlamp housing. That solenoid rotates a shutter to either block, or not block, the upper portion of the LED light beam. The left headlamp ECU forwards the high-beam / low-beam command to the right headlamp ECU via a local digital communication bus (LINbus).

In theory, one could temporarily remove either headlamp assembly and connect to the solenoid wires I do not know if the solenoid operates at 12V, but suspect it probably does. A relay connected in parallel with either solenoid could be used to switch a separate fused 12V source to the light bar. If you are interested in this approach and would like to see images of the solenoid wires location, I can post.

heistnorway

Thanks alot for this post!

I went out and bought CANM8 and the plan is to connect to the lexus CAN bus system to retrieve signal for high beams. CANM8 will send signal to the the switch that gives power to the led bars.

Hopefully this will work, but there is little to no guides out there on how to do this on lexus