Took my 2004 kia amanti in to replace head light and fog light. Instead they had to do a diagnostic check. Discoverd that the function box is faulty and will cost $600 to replace. I just took car home. Now the electric is out on my dash (odometer) and lights do not turn on at all. Taking it to another mechanic. Could there just be a wire loose or something?

Possibly. I'm pretty sure your Kia has Xenon high density headlamps? For these later model vehicle where everything is computerized, it is hard to diagnosis anything without the right tools! Scanners, programmers and testers of all sorts!

Check all fuses and relays in the interior and under the hood do thus visually at least make sure none of the filaments in fuses are broken. Even the freshest novice can accomplish this and you jist might save yourself a lot of money. As for relays check which each do accoriding di diagragm on cover or owners manuel. Most relays are exactally like thier neighbors. So take one from simething that you kniw works like the starter relay and replace it with one your not sure off like the headligjts swap the two if the starter still works you know the headlight relay is good continue to eliminate all potential faulty. Relays. Sometimes the smalkest things save us plenty money. Check those fuses and relays first

Please make sure you take it to a good mechanic ( MECHANIC ELECTRICIAN ) that specialized on electrical only