...here's how you fit the cable.
Remove air filter
Unplug wire from air idle control valve
Plug in test wire on air idle control valve and connect wire on the car to the other end
You've then got two plugs to somehow fit to your multimeter / ammeter
For this there's another test wire (I guess) but because it can be pulled away from the car and away from harm I'm going to use some old fashioned 4mm banana plugs so I can secure some crocodile clips to the ends.
Everything is going to be taped up so I can't ground this connection with the chassis by accident.
Note:-
This cable is essentially disconnecting the existing wiring loom so that an ammeter can be connected
in series
If you leave the test cable in place with out a connection to the ammeter / multimeter then the idle will be high => because the control valve is effectively disconnected. Connect the measuring instrument - make a reading - and the valve works (hopefully).