Vibration of steering wheel while bracking in Mistzubishi montero sports 2012

You need to determine if it's the horn or the alarm. My Montero (not Sport) had 3 horns. All 3 of which go off w/ the Alarm, but only one is connected to the horn on the steering wheel. I could not make mine go off w/o pulling the relay under the hood.

My spring was bad in the steering wheel. I was able to bypass the wire using instructions that I actually found on a Mitsubishi Forum. Link below:

http://mitsubishiforum.com/forum/mitsubishi-montero-montero-sport-14/horn-wouldnt-stop-2003-montero-limited-how-i-fixed-37779/

or

http://www.pajero.guru/how-to-fix-pajero-stuck-horn-problem-step-by-step-guide/

Check the connection to the horn? be sure they are properly grounded. Also the horn switch on the steering wheel may be not making a connection with the ring plate behind the steering wheel and before the column.

Probably the contacts in the steering wheel not making contact anymore.

There are 2 fuse boxes, one is near the hood release on the drivers side below the steering wheel left side, the other is actually under the hood on the drivers side

vibrations in the truck and the steering wheel moving im assuming small movements left and right sounds like you have a broken tred or belt in one of the tires i would start with the front ones because of the movement in the steering wheel. it dosent do it at lower speeds because it takes a certian speed to cause the tire to roll out of balance this is probily the feeling you are getting in the steeringwheel and in the truck over a certain speed. its had to spot but sometimes you can jack up the car and spin the wheel by hand without removing the wheel to see if there are any lumps or high and low spots in the tire as it turns. as i said start with the front tires they are the ones that will cause the steeringwheel to move like that.. if you have tires that are under warranty they might do this check for you. the car will stay in allignment and hold good pressure if this is the problem.

Sounds like you may need a new power steering belt, or have the belt tightened. I would have the other belts inspected too.

First check the fuse for the horn and see if it is blown. if that is ok, check the switch/button in the steering wheel where you press the horn to see if its making a connection.

did you check the lock mechanism under the wheel at the dash? you have to relock the wheel it sounds like by pushing the lock lever

Could be a wheel bearing and/or a rear differential pinion bearing, which usually get worse when under load(going up hill). I would definitely start there.

Have you tried cross checking with another wheel alignment specialist? To me it seems to be coming from the tyres or a dented rim. You could ask them if they do dynamic wheel balancing on the car itself. This will take in consideration the out of round of the hub as well.
Let us know if there is any change.
Cheers.