Can anyone point me to some good instructions on how to install a new 2 speed on / off switch? I am installing a down-draft evaporitive cooler (swamp cooler) on my roof and can't quite figure out how to wire it in the existing wiring. any help would be greatly appreciated.

I had a professional check my unit today, June 12. He told my wife there was no freon in the unit. He recharged the unit and told my wife it has a leak and will probably need a yearly recharge if the leak isnt too bad. He told her he checked the visible parts of the unit and found nothing. I will be in the attic next week for other reasons while up there how do I check the line ( visibly ) for a possible leak? At my work I test welds for leaks with soapy water while the unit is under pressure, will this method work the same for this as well? the unit is a Bryant and in good condition ( or at least it looks good from the outside ) and doesnt seem older than 5 years or so old. My house is built on a slab so all plumbing is in the attic and outside. The unit went down last summer and i couldnt have it looked at until now, but before that i used it for a season and a half. I hope that gives you enough info. on the problem. Thank you for your help El Jefe Metro Detroit Mi.