A/C Blower issue

I have installed new ignition switch, blower regulator, and blower works fine with 12 volts to it. It works for about a day then stops, I feel cold air just no blower. any ideas? By the way this is a 93

You have to look for the problem, when it is present. If blower will work when applying 12 volts directly to it, but not when connected normally, the problem is in the control circuits (incl. regulator).

Otherwise I would suspect the blower motor. Brushes and commutator will wear down, until the connection fails intermittantly. I had that problem.

Unfortunately you cannot buy the motor by itself, but only the complete blower assembly, which is quite expensive.