So i tried to start my 2004 Mazda RX8 today and nothing happened. I took the crank off and checked if it was working and there was nothing wrong with it, but as soon as i put it back on my car it won't crank or nothing. if anyone has an idea of what it could be that would be amazing

 

What do you mean by taking the crank off?

 

I'm guessing that by 'your crank' you mean your starter motor. It sounds like your engine may have carbon lock - but before we assume the worst, try removing your starter motor but leaving the wires connected and then attempting to crank it. (leave your drive door open and listen carefully) If you don't hear anything, then you know it's not getting power from the battery, and could be as simple as a fuse. If you hear it spin up, then your engine's probably seized and it may be worth trying a decarb with ATF. However carbon lock is quite rare only usually happens on high mileage engines that haven't seen the redline very often...

 

is your little car with a key light blinking?