Well i messed it up this time lol
I thook out the battery in my rx7 so i can let it charge. When i put the battery back in i notice both cables wher black but one had a yellow strip on it. I put the black and yellow cable to positive, and the all black one to neg. I then walked over to my camaro when i looked back i sall some smoke comeing from the rx7. When i got to the rx7 the wire on the Alternator was smokeing. I unhooked the battery and then let the rx7 cool down. I then check all my fuses and notice 2 had blown, so i replaced them. When i went to go start the car the rev metter did not work, and my speed metter did not move, i never did put the car in gear to test the speed metter.
Ok now that you are done laughing how can i fix this
I hope i just need a Alternator and a ECU....

 

You may not need an ECU just yet- the only input that I know of that's energized with the key off is the "batt" pin...Of course, you just put +12vdc on all of its ground inputs, so who knows?

The alt diode bridge (rectifier circuit) is the most susceptible to reverse polarity, I would think...

Blown fuses are good- hopefully they blew fast enough to protect the circuits from further damage...

Let me guess- the main fuse blew, and...the other???

 

it was a 20 and 7.5 fuse that went

 

20 and 7.5? Both in the cabin fuse box?

Did you get her back up and running?

 

If fuses dont fix it, you probably need an ecu. I've seen this before. The alternator should be okay.

 

I'm amazed the main fuse didn't go out with the bunch.

 

Yep mine went out right away when my friend decided to "help me" and put it in backwards. the horn went off and the fuse blew right away.

 

Have you checked the main fuse yet? Its is 80A in the engine bay. If you haven't that could be the cause to your problems, check that before going and buying an expensive ecu or alt., since its only like a $2 fuse. When mine blew I thought something was seriously wrong with the electrical system, the cabin lights would come on but nothing else would work, scared the crap out of me.

 

ya my main fuse went also when MY friend decided to help!! It was a bitch to find one too!!

 

Did it start? its sounds like he started the car but the tach didnt work. O and btw the speedometer is gear type mechanical...

 

I accidentally just did this too. I havent changed out the fuses yet so im not sure but i hope thats all that went.