Ok, So i Left My 8 with my wife while i was gone (Military Reasons)... And i come back to a 8 that will not turn over. Then she said "she told a mechanic did some thing to the car (she doesn't know what). So yeah the car wouldn't turn over and i realize one the battery wasn't even securely tightened down. As i tighten it down the car dash won't turn on and neither will it do anything when i turn the key. i know this Rx8 needed a lot of work but I'm willing to spend the money. Wanna know why is it acting the way its acting after tightening batterie. if someone will help. I will take video and pics or even camera to camera someone and show them whats going on. Just need major help.

 

Try jump starting. Sounds like an utterly flat battery. Make sure you leave it on to warm up/charge for a good while if it does get going though. Otherwise you'll flood the engine, and have weak spark to try and start it again with... Might be worth waiting for a more experienced member to confirm though.

 

To be honest, I'm guessing the car is already flooded... I would get the battery fully charged, most auto stores will do this for free and then try and start it again. if it just cranks and cranks, then it's definitely flooded to you'll need to follow the de flooding procedure.

 

I would agree start at the bat. With the weather like it has been that could be your problem

 

Im going to attempt taking the battery out my other car and trying it on my 8. And see if it still the same problem.
- I attempted to jump start and nothing at all. My dash illuminate when i have key in nothing. It gives me the key light but everything else is completely off.

 

Could be a fuse if it isn't the battery. Could be this mechanic pulled the main fuse to do whatever he was doing, and forgot to put it in again. Try the other battery first though. Again, this is wild speculation without actually seeing! And I'm fairly new to the car :/

 

Sounds like the battery connections may have not been tight. Make sure they are on real nice and tight. Usually if the head lights will burn at full illumination, it's enough to turn the starter motor.

 

@Ninja - I checked most of the fuses but not all them. I didn't know which fuse exactly to look for. I was gonna just change all them and hope it works lol but to me it seems like the battery because not even the lights on my dashboard isn't even turning on. i can't even open the trunk. So its seems like a power loss somewhere.

@Kevin - To me i thought it was the same but when the batterie was actually untightened i had some sort of power. Then when i tightened it for some reason i got no power whats so ever. it was a weird event. i took the battery out and then put it back and i got no power whats so ever. I'm about 100% positive the battery is connected right because I'm not idiotic. i can work on a diesel engine for the Army but there rotary engines are giving me trouble

 

no power nothing no lights at dash at all ?

if u're sure ur battery has power, it's time to check fuses, and if ur battery has power and u're not getting any light, check the 120Amp fuse on the side of the fuse box.

 

I'm with nycgps. If you are certain the battery is charged, time to start checking fuses.