horns usually do work when you put pressure on them, as for the airbag light nissans are usually good with their srs systems, check the seat belt pre-tentioners, where your seat belt clips into, if one is lower than the other one of them has been activated, if they are both at the same level look at the tube attached to the pre-tensioner if the wire is at the end of the tube, both have been activated, if you are experiencing problems with the horn, maybe someone has taken the steering wheel off and not correctly aligned the clock spring, this is attached to the steering wheel and allows a electrical connection to the airbag, and as the wheel turns, has enough spring to go from lock to lock, so the steering wheel must be removed with the wheels straight, and the clock spring locked in this position, these are the only problems i have ever had with nissan srs systems.
