Problems accesing to child actor function

I have this Blueprint with two child actors joined by a physic constraint. Each child actor is a pawn with a vehicle movement component and both work correctly by it self. But when I use this Blueprint I can not make the wheels rotate with the throttle input. I used some tips from the forums but still is not working.

I need this set up for this vehicle because it is the only way I found to get the physical behaviour I need. This vehicle turn right or left by rotating the front and the rear body in opposite values.

I don´t know how to control the wheels, I´m stuck on this. I have not found a vehicle like this on forums.

Thanks in advance

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