Silverado ABS issue
 

Greetings all. 2001 Chev Silverado 1500 5.3 4x4: Issues I'm having is ABS and Brake lights are on, speedo doesn't move off of zero and it will not shift. So far I've replaced the 2 speed sensors on the transfer case, the ABS Module and the ABS Pressure Valve. I've also just finished installing new wheel speed sensors on the front (none are called for on the rear). After installing the 2 on the front I was able to drive it 45mins before the ABS and Brake light came back on with the speedo and tranny doing the same as before. However now it also starts pulsating the brake pedal when I slow down to 8mph...every single stop I made. I've also cleaned the ground on the frame and put in a new bolt, washer and nut. Going out of my mind getting to the bottom of this. It's my only transportation to and from work. Help, help, help please!!!!