Sorry to bring this thread up again, but it saved me alot of money. For 3 years my a/c hasn't worked, tried to charge it and even changed the low switch, to no avail. What apparently was happening is... Since i was low on refrigerant, the low side switch was actually working and not letting my a/c turn on, i had to jumper the low switch just to bump up the pressure high enough for the switch to engage the a/c. Hope this thread helps some other people in the future.