380sel throttle switch

[merc380sel]

How do you know when the throttle switch is not working.
I tried disconnecting the 2 pin connector to the switch while the engine is running and noticed the idle rpm remain the same.

Also, is it possible to bypass the idle speed control unit electrically besides applying restriction on the idle control valve?

I asked this because I noticed that with my idle control unit disconnected, there's still current going into my idle control valve and when I pulled the 2 pin connector out from the idle control valve, the rpm surged to 1500 (900rpm when connected).

I am not sure if I should replace the idle control unit first not knowing if the one in my car is still working or not.

There is no any restriction in the idle control valve anymore but the rpm is still doing 900 with the idle control unit disconnected, and 1500rpm with the 2 pin connector to the idle control valve disconnected.

Pls bear with me, Steve and all who are able to help me out again.