Will Increasing the Voltage Affect the Functionality of My Circuit?

[michael7777]

I want to modify a circuit by adding a stronger drive motor.

The circuit is a PCB receiver which is attached to two motors, one which steers a car, one which drives a car.

The previous drive motor needed 2 x 1.5v batteries.
The new drive motor needs a 12V lead acid battery.
This means that 9 more volts will run through the circuit

Here is a block diagram:

Here is the annotated schematic:

I have more information about resistances if there is a need for it.

I am unsure of if the components will still work with such an increase in voltage. So it would be good if someone could advise.

 

[NoTime]

The first problem is that your annotation of steering and drive motor on the schematic is reversed.
The other is that substituting a 12v battery will burn this circuit up.
Some of the components could be reused but major changes are required.

 

[michael7777]

I knew the 12v battery would kill the circuit. Since I am no good at making circuits ill just stick to using the slow 3v motor.