Can the electrical system be fried if you hook up the battery backwords (poles reversed)?
I'm asking this because after taking the battery for a check at Advance Auto Parts, they offered to charge it. But when I took it back to the car and hooked it up (correctly) it sparked and everything went dead. I took it for a check at a specialized battery shop and they showed me the poles are reversed. Plus is actually minus and vice-versa. I told the guy the whole story and he said the guys at Advance Auto Parts reversed the cables when they charged the battery.
Could this be possible?
Is my car's electrical system fried now, and how can it test it? I checked all the fuses and they're good...