Roof lights, clock, car radio and dash lights not working anymore after I did this

Greetings fellow drivers !

I have an unfortunate problem these days on my 1984 2 seater turbo.

Everything used to work perfectly, radio, lights (all of them), clock, dash…

Then I tried to swap my radio head. I took the old one off, found out that the harness was different for the new so I cut the wires to the harness head and fixed my new harness' wires.

I did everything according to the colours on this post :


I had no problem doing so. I just did the power, switched power and ground to check if the new radio was at least turning on and it wasn't. More than this, the clock above the AC wasn't working anymore.
I tried to troubleshoot it by checking the fuses (driver panel kick are all fine) and tested the power (no constant power !).

So it seems something related to my constant power source is messed up, but I don't know where to look.
I also found out my roof lights and dash lights are also gone.

I'd really appreciate if you guys could help me !
Should I just go to my local car shop to ask for help..?

Thanks in advance, hoping you guys have a wonderful day !