Power windows, heater, and radio stopped.

I am going through the same thing. I have an 04 pacifica. I have narrowed it down to a couple of reasons. The relay switch, the red wire connecting the battery to the main fuse box, or there is a recall on the the fuse box itself. I'm not sure either of which but I have good mechanic whose gonna keep me posted.

Check fuses front black box, check circuits and may have to replace the relay ground. Power modules has to have a ground and the relay has to be grounded as well. The integrated power modules are notorious for failure, however before going to that expense make sure all your modules are grounded using a tester. Hook up to the positive on battery the other to ground that may have problem as sometimes you need to cut the wires if they have green oxidation then put on a new connector and reconnect and see if that solves the problem first.