How do you fix my blower motor in my Nissan Titan?

Start by diagnosing to identify the problem. Have the relays and fuses been checked? Is there power going to the blower motor? If so, does it go to the blower motor on all settings, or just on the high setting? If that's the case, it's the resistor you need to replace. If there's no power going to it, you need to see if power is going to the blower switch, and if you have continuity at the switch. If everything checks out, and the blower motor doesn't respond when power is applied to it, you need to power and ground it from a separate source and try applying power again. If it works at this point, you have a bad ground, and need to repair it. If it doesn't, then the blower motor is bad, and needs to be replaced.