Hi Tony,
You will need to make your own harness, with wire and corrugated tubing, you can buy at any auto shop. If there isn't a published wiring diagram, with colours, then I suggest you work out a colour scheme, so when you have the end of your harness you know which wire is which. As to the clutch switch, I've fitted a standard micro switch, on a home made bracket. The switch is wired in the normally open connection, as it is operated when the clutch is up.
Note, the attached article is for my MGB brake switch replacement, but it will give you an idea about how to go about it.
As to connecting to the ECU, if you do need to do it you only need to connect to the speed wire. If you have a tacho, then you could tap into the sense wire to it, using a quick splice connector, as shown, below. They are closed with a pair of pliers. Note that they come in different sizes, depending on the wire size.
Herb
Saga19 Brake switch.pdf
I know there is a heap of discussion out there on this topic but has anyone successfully added cruise when the wiring harness doesn't support it?
I was a hoping to just buy the clock spring and cruise stalk and fit it, but mines a manual and there is no wiring to connect the clutch switch to. I've read about people running wiring to the ECU, but there weren't any clear guides for this that i could find. How do you actually tap into the ECU connector because the pictures I've seen look like it wouldn't be easy to add anything to it?
I gave up after seeing there was no clutch switch cabling to wire up to so I don't even know if the necessary cabling is between the clock spring and the ECU.
Has anyone done this mod on a car that isn't pre-wired for it?
Just purchased a 2008 Corolla hatch. As shown in the photo, the rubber shroud attached to the handbrake sags down and leaves a big gap for things to potentially fall down in there. I can't figure out why its like that. Nothing seems to be broken - is there something missing from there?