Temperature guage, rear view mirror reverse camera died

Hey all-

So I had my alarm replaced and the truck came back with the following-

Temp guage reads --- now. Compass still functions fine though.

Rear view camera screen in my rear view mirror never comes on. However I do have a secondary wired to my AV system screen, but that comes on... when it feels like it. They used to both come on instantly anytime I tossed it into reverse.

Something is screwed up, maybe 2 things. I'm asking here in that the company that did the alarm system just got argumentative when I showed them what was up, and frankly I don't want to let them screw up any more than they already have. Also I can't shake that whatever is wrong is probably some weak wiring that got jostled when they redid the alarm.

Any ideas, or links to threads that I should read up on (I think there's a soldering fix for the temp guage but I haven't been here for about a year so I can't remember) feel free to toss my way. And thanks for doing so.