Help speed, rpm and ac not working

So I've been having this problem with my truck. It is a 2000 Peterbilt 379 3406 e cat. I turn my key to the on position everything seems to be working fine rpm, speedometer, fuel, water temp, and brakes. Once I turn my truck on it works for a while, but then it all stops working; rpm, speedometer, water temp, fuel, ac control, and even the brakes. Does anyone know why? I recently changed the oil pressure sensor and that's when the problem started.

 

Brake lights yes.

 

I'm lost in this I'll just take it somewhere tomorrow. The battery discharge protection system is blinking so idk what it could be. Could it be the box itself? I doubt it but I checked to make sure my battery cables where on there right. And I checked behind the gauge cluster to make sure everything was good. Dont know what else to check