High rev problem

[stratosTRD]

Hi
I have a recent serious problem that i need your help if somebody can help me.

Some time ago i wanted to find a cable that i can cut it off with a switch so that my ae86 wont start.
As i was searching near the ecu i found one with black color and a continuous red line running along the cable with red circles also with about 2 cm space between them. I cut it, inserted a switch and the car didnt fire up. With all this mess of cables i could not find what it was, except that it was going at this yellow plug that you can see in the pic.
The switch worked perfectly with only one remark. When sometimes i forgot that i had the switch off and tried to fire up the car it made a sound like a relay trying charge repeatedly and only when i turned the keys to ON position it stopped.
Of course when that happened i immediately turned the key to ON position so that i wont create any problem.

What happened 2 days ago is that i parked at my house and i turned the switch off before the keys of the car. So the engine started to go off and after a second, before i could turn the keys off, i started reving high at about 2000 rpm. Immediately i turned of the keys.
After that and until now when i start the car it revs immediately at 2000 rpm all the time my ae86 runs. No matter cold or warm engine.
And also the switch isn't working anymore. On or off its just the same, like it doesn't exist.

Anybody familiar with any solution?