Well here is the deal, I got an S4 GTX (TII in the states) and i was doing some touge with a couple of friends, I spon out and hit the rail, well i open my hood to check the damage. I took out the battery to hold my bumper with a cord, but i was so in a rush that I put the battery the wrong way and the burned the main fuse, change it with an other one since i had a wiring harness on my trunk.
The car didn't start and i could hear the fuel pump turning on ones i turn the key to the on position and all the power will just go, my turbo timer starts turning on an off while I crank so as my dash and my tach will go backwards yes backwards from 0 to 10k rpm and each time it cranks one step back, 2 cats driving a couple FCs stop to help us but since i speak a crappy japanese i call my wife so she could translate but since she doesn't know car terminology they could help but they call a tow truck for me. now the car is on my parking lot and i got an event coming up and need my car running please help!! by the way i try boosting the car with my friend car but didn't help either, same problem. (aftermarket tach)

 

i'm goin to take a stab at it and say either a fusible link(s) or diodes..and the only diodes i can think of are in the alternator..as i said though..it's a guess..you checked all fuses in the engine bay and in the interior too?

 

I check all fuses, engine and in the cockpit, the only one that god blown was the main fuse and i already change it, but all my electrical works, lights, dash, turbotimer, doorlights everything. but when i start cranking is like the battery is low i try with an other good battery and the same thing, i tray using the cables with my friends car and the same thing happend. indoor power come and goes, on and off. I can hear the fuel pump each time i put the switch in the on position and i never done it before

 

when u turn the key to start see if you have voltage at the starter if not it a blown fuse

 

The engine cranks but it does it like when you battery is low, even if i use a good battery or boost it up with an other car

 

you still could have crappy voltage at the starter making it not turn as fase... it sounds like a ground came loose somewhere when you hit the wall

 

sorry didnt read the whole post

starter maybe

 

see what the voltage is at the starter with a voltmeter

 

check for a ground

 

Well i don't know the car kept running after i hit the wall, and it wast that big of a damage only my bumper got mess

 

my guess is something electrical to the starter ground or power i have the wire diagram at work will look at it tomorrow

you might be able to find it online

 

you probly shorted out the starter and alternator. most likely fried some of the ecu, the only way i can think to check that easily is to just check some outputs on it like at the tps and see what sort of voltages you get out of the ecu.

 

I would like to know how to check that

 

yeah how you check that?? and for how many volts should i look for?