Just changed the heater core in my truck and got everything hooked back up…now the instrument panel is not working, the radio has no power, and the hvac is not working…no power to all three…hooked up all connections that go to these, but nothing. Did I miss something that would cause only these three things to malfunction???
You likely lost the ground connection to the panel. You also could have lost the power supply due to a bad connection as well.
Did you check the fuses?
I’m going to square one you here. Remember that wire you moved? You may have to push the connector back together. My other favorite is the fuse that just let go for no reason.