power stearing prob!

ok in the past couple of weeks its been super cold here (like everywhere right now) but since its been cold my power stearing well left me or so i thought.

when its warm it works
i just about changed the pump (but thats not the prob)
i took it to my local honda cause i was out of ideas
after one day of looking at it they basically said that the pressure switch is missing off the engine harness.
easiest away around this buy a new engine harness
(i don't want to do that)
has anyone heard of this before its a US engine
did us si's not come with this switch?

I NEED HELP!