What i did
I tried installing my new e-manage to my 89 S5 turbo 2.
When i have soldered and checked the connections from the e-manage harness to my passthrough connector.

I followed e-manage manual and when i tried to connect to the emanage it said online but could not download any of the e-manages info.

This did not worry me since the car should still run with out the my pc connected to it. Since it is a default configuration.

So i connected back my stock ECU and treid to start the car and nothing...

Symtoms.
When i turn to ingition key to the ON position the car seems to be fine. All the check light turn on and so does my Apexi AVC-R tun on too.
I check that my throttle position sensor was working by checking the AVC-R sensor check.

When i try and start the car everything just dies.....
I also hear a loud click from the engine bay but can not determine what is wrong.
I have to disconnect and reconnect the battery to get the car to get the car to tun on in the ON position.
Interior lights become very faint.

I have checked my fuses in the engine bay and below by the clutch.
I have checked that the ECU is getting power.

Questions.
1. Are there any other locations that there could be fuses?
2. How do check my ECU that it is functioning correctly?
3. What else could i do check?

Tried searching but area of search to large....