Speedometer on 1995 GMC 3500 is not working ,and the brake lights don't work.

What is your question?

The speedometer sensor on my 1995 G3500 gmc was changed and the speedometer and brake lights worked fine for 2 days. Neither the speedometer nor the brake lights are working now. Is there a reason for these to break down at the same time? The bulbs look fine. They light up when I turn on the headlights. The fuel gauge is not working properly. The fuel pump pressure is at 17pounds, it is supposed to be 18 pounds. Do you recommend to change the fuel pump?