I have an older Kennmore dishwasher 665-15805 that won't turn on. Does anyone know how to reset it?

Do you have power in the connection box under the DW? Control board lit? Try shutting off the breaker for 2-3 minutes and then close breaker. Any change?

You need to get a good meter and learn how to use it. Here are some manuals: https://dl.dropboxusercontent.com/u/8010163/Electrical%20Theory%20and%20Diagnosis%20of%20Major %20Appliances%20Service%20Manual.pdf
https://dl.dropboxusercontent.com/u/8010163/Whirlpool_Kenmore%20Dishwashers.zip
https://dl.dropboxusercontent.com/u/8010163/How%20to%20use%20Test%20Equipment%20Service%20Manu al.pdf
https://dl.dropboxusercontent.com/u/8010163/Kenmore_Ultrawash_Dishwasher.pdf
https://dl.dropboxusercontent.com/u/8010163/Whirlpool_Dishwasher_Service_manual.pdf