resistor box not getting power main relay acting weird

Ok… so it started with my car not want to start one day went through the general procedure of starting with my main relay. After doing a quick diag. I deamed it failed(fuel pump not priming I jump it car fired up) I bought a new relay didn’t fix the problem. So I borrowerd one I new was functional out of a buddy ef civic still no start but now the iacv was goin ape shit. We ended jump the resistor bow side of the relay and every thing went back to normal. I decided to take the car around the block but the seat belt dinger would not stop going off ,and the rear defrost light would was on regaurdless if the switch was on or off. I’m beyond confused any help or input would be greatly appreciated.

your defrost and seatbelt chime sound like an icu issue.
as gor the MFR and IAC, start by cleaning the thermostat housing ground point