Why do we have to reset our coleman evcon when it goes thru its cycle, for some reason blower does not come on?

The reason you have to reset the furnace is the fan is not coming on & the furnace is overheating. Why the fan isn't coming on is another question. Do you have a voltmeter & know how to use it?

Yes I have a Voltmeter. I now some of it. What do I need to do.

You have to find out from where the fan motor gets it's power & check for 120 volts AC between that point & neutal or ground. This must be done when the furnace is hot enough to bring on the fan. If you get the 120 volts but the fan doesn't turn on, you probably have a bad fan motor.

Thank you for the help. It was the fan motor that was bad.

Glad I could help. If there are any other problems, we're here & will do our best to help.