LED/HID lighting upgrades confusing 7" VGA car LCD illumination
I installed a car PC in my Mazda 3 MPS (2006 model), with the +12 illumination wired up and working well dimming the screen when the headlights get switched on. The setup is a Mini-ITX AOpen setup with CARNETIX PSU and a 12V 7" HDMI/VGA LCD.
Recently I replaced all the internal globes with LEDs, and then the headlights with HIDS and some LED lights externally (eg. number plate, parker, reverse lights). They all work perfectly without issue, but I note the dashboard displays a "globe blown" icon suggesting some sort of CANBUS/low voltage issue. I do not believe the Mazda 3 is picky with CANBUS issues as much as some other cars, in fact there is next to nothing online about this fault I am having.
I can live with the error on the dash, but the 7" LCD illumination is strange. It'll now flicker to bright when I switch on the lights, then back to dim again. When I turn on the foglights, the LCD goes bright (it should dim). Obviously the car is getting confused about the lower voltage of the LEDs, as is the illumination of the LCD.
Would wiring up a load resistor on the 7" LCD illumination wire help things, or any other suggestions? I could try wiring up the LCD to it's own 12V dimming switch but have loved the current setup