The kids decided to install a new stereo in my 02 Malibu on the weekend. Unfortunately they didn't know what they were doing. Now, the following doesn't work: factory stereo (which they put back), fuel and temp gauges, cruise control, auto lamps, daytime running lights, and key warning chime.

I've checked every fuse under hood and at each end of dash. Any ideas???

 

While they were working on the stereo the must have disconnected something or connected it incorrectly.

 

There is just a single harness behind the stereo. I can't see anything else they might have disturbed. Unless they damaged a pin on the stereo harness connector... But I can't see all those components being reliant on a single wire connection into the stereo. I'm thinking they must have shorted something. I'm beginning to wonder if it's the ignition switch or the BCM, but both control other functions that are still working (ie. the interior lights).
I also haven't checked the relays yet. It's been a while since I tested a relay so I don't recall which terminals on a relay should have continuity?