I'm trying to get a 2000 Blazer up to speed. The AC was blowing the 30a HVAC fuse so I replaced the seized up motor with a VDO motor bought form Autozone and it started working. The catch is that only the 3 and 4 fan speed would work; 1 and 2 were dead. I then replaced the blower motor resistor with a Duralast resistor and it worked for a day. Now I'm back to where I started. Only the 3 and 4 speed are working. I've checked the wires on the motor and resistor and they appear ok. I haven't replaced the blower motor relay yet. Could the relay cause something like this?

Original resistor