I’m planning to upgrade audio and disable canton. I want to make a contra connector for the T38a pin connector to the car speakers to connect it to my speaker out of the new dsp amp. I find the pins for the speakers (see file) as I’m reading it correct. 
 

Is pin 1 the power in and 2 the ground?

 

and in the diagram the number on the wires (4.0/2.5/1.5/0.75) are these thickness of the wires?

Bedrading.pdf.pdf

The number is the wire thickness, yes.

 

The wire at pin 1 is the power, pin 2 is the ground. The little box at the top of the red wire relates to a location that is found along the bottom of the page. 

Disabling canton means coding out the amplifier and running new wires from the back of the headunit to your new amplifier. I wouldnt recommend taking your amp input from the already pre filtered outputs of the canton amp. 

Thanks. Yes agree. I have new cable from the headunit to the driver seat to the new amp. From there from the amp to the speaker connector. Do you know how many ampere is on the power? Maybe I could use it to feed the new amp.