Ok i just got my pioneer 780 and me and a buddy hooked it up...The hu works fine but my instruments on the dash, like the spedometer, fuel gage, rpm gage, and all the sh!t like that doesn't work. I've checked all my fuses and they aren't blown...I'm very positive the hu is wired correctly...
Probly a relay. Look for anything labeled intruments, cluster, gauges. he may have pulled a connector out too if he was fishing around up there for stuff. And you should check fuses again with a continuity tester. Sometimes they look ok, but are broke at the end where you cant see it. Go to the HU section and see if someone can give you a wiring diagram for the dash area.