Semi-overheating?

[epapp]

Could just be the low speed fan relay.

If the fans are not on due to temp and you turn on the AC, both fans should activate to the low setting.

I haven't tested turning on the AC when both fans are on low due to temp. Do they go to high speed operation if AC engaged when low speed fans are already on?

If your car is cold and you turn on the AC and the passenger fan still is dead, then your relay for passenger low speed is dead, which is simple and easy to fix.

If you do the above and the passenger fan comes on low speed, then I have no idea.