Just did transmission replace my heater core an it start but want stay on

Hello, I am the only person I know that enjoys removing and installing the dash to do a heater core job. I do them in about two hours, max, because I have a system that works. The most important part of that system, and likely your issue, is that I only detach the plugs that connect the dash to the car, not individual components. When disconnecting each thing, or anything unnecessarily, it costs time, and inducts risk into the situation. The risk of pinching wires is as at peak when wires are removed from their factory location. Go in, pull the dash, clip or zip-tie the wires where they were from the factory, use pictures if you need to, and see which wire is actually cut or folded over something. Replace that section of wire, and put it where it goes. Let me know if you have ANY questions.