Sync 3 with Hazard light / door locked backlight problems

Hi all,

I just upgraded to Sync 3 from Sync 1 on my 2013 Focus ST. After using a conversion adapter to connect the original 8-pin dash plug to the new hazard light / door lock button, the button backlight stays permanently illuminated—even after the car has been turned off all day.

My wiring setup from the switch to the original 8-pin plug (left to right, High to low, 4 pins upper 4 pins lower) is currently configured as follows:

Pin 3: Button backlight ground signal
Pin 4: Hazard light flash trigger
Pin 5: Constant 12V power
Pin 7: Door lock signal trigger
Pin 8: Ground wire

I verified with a multimeter that Pin 5 on the original plug carries constant 12V power, which explains why the light stays on. My current wiring is shown in the attached picture. Could anyone advise on which pin/wire I should tap into so the backlight turns off with the car, or let me know if my pinout is incorrect? Thank you!


SYNC Region: CN

Navigation Variant: Non Nav

Manufacturer Year: Pre MY20

Install Type: OEM Replacement

Old SYNC Version: 1.1.511

New SYNC Version: 3.4 23188

Do you have a error message, if so what is it?
no

Update Method: CyanLabs Manual Method

This isn’t a Sync3 problem, its a harness/adapter issue.

Have you contacted the seller?