Ok, it is not a simple on/off switch that is used. It is a special Anti-Lock Brake Breakout box/Bleeding adaptor that is used. It controls the actual bleeding of the ABS unit, nut jst supplying power to it. Straightwiring from a 12v source will only short out your ABS unit, PLEASE do not do this unless you want to buy a new ABS unit.
The anti-lock brake system must be bled in 2 steps; both the master cylinder and hydraulic control unit reservoir must be bled using Rotunda Anti-Lock Brake Breakout Box/Bleeding Adapter tool No. T90P-50-ALA or equivalent. If this procedure is not followed, air will be trapped in the hydraulic control unit, and will eventually lead to a spongy brake pedal.
First, check the Autozone and Discount Auto Parts near you. Some locations rent this special Breakout Box/Bleeding Adaptor.
If they dont have one. You have 2 choices: