A/C blower only runs when switch is on high. Is there way to fix lower fan settings?
What year Nissan?
That’s what happens when your blower motor resistor goes bad. It’s mounted in the plenum so the air from the blower motor keeps it cool. Either follow the hot wire from the blower motor to find it or pick up a new blower motor resistor and play “where’s the part that looks like this” until you find it. It’s near the blower motor either under the hood or under the dashboard.