If it was blowing cold then u didn't need a blower motor.

Make sure the heater core hasn't been bypassed. Look under hood on firewall to verify connection. Should be 2 rubber hoses. In and out.

Check to see if thermostat is installed.
If no t-stat is installed then engine temp has to come up before heat will be produced.

After engine temp elevates to norm operating level then try heat. If no heat then heater core is bypasses. Or your temp gauge is not on hot side.