Blinking lights

In Hong Kong Light rail vehicle there is an direction lights outside to indicate where the train is turning, just like buses. In the cab there is also an indication lights indicate that the direction lights are active. However it start to blink on when either left or right direction lights is active. I want to recreate it in OpenBVE but I only got either left or right working. Meaning I can't get both to work, is there anyway to do this? Thanks.

I think I would have to see more details to help.

First of all, if I understand correctly you want both of your direction lights - left and right - to blink at the same time? And also the in-cab control lights for both the left and right direction lights to blink at the same time?

In some buses, there is an direction indication light in the panel, however doesn't indicate did the driver blinked left or right

I just want to recreate that, no matter which side it blinks, the indication light will also blink(with the same texture for left and right)

If I understand correctly, you should just have the same animation code for your in-cab indication light as you have for the outside of the vehicle. Do you have the code for that? Is this what you mean?