1) The A/C is tripping off and on. It comes on for like 20secs and then trip off for more 4mins or longer. At the time it stops cooling, the fan blows well but not cold. What could be wrong with the A/C system?
2) There is temperature sign (like the symbol of a thermometer) that comes on intermitently. It comes on and goes like every 2mins. But the engine temperature indicator does not show any overheating. The indicator is slightly above 80deg Celsius when the thermometer sign comes on and then the temperature indicator drops slightly below 80deg Celsius when the thermometr symbol is off. I don't understand the problem that this sign represents.
3) Again the fan comes on once the car engine starts or even just when you turn the ignition. The fan blows at full speed and very noisy. Is this normal? I thought the fan is supposed to come on after some minutes of the engine running and then trips intermitently depending on engine temperature.
Please tell me what is wrong with this car as it is a fairly used car that i just bought.

I checked the fuses and, in my owners manuel, it does not show a fuse for the horn!!

First drive in the morning the car shakes as I drive for maybe about 5 min. Guessing it does that till the bad part warms up. After the initial 5 min the shaking goes away, but I feel a vibration coming through the seat. At 100 km/h it's at it's worst. Just dropped $3000.00 into new tires, struts, control arms, rear springs (broken) and an alignment at the dealer. At highway speed I dropped the car into neutral and coasted to a stop. The vibration never went away.

How do I know if this is a result of a bad fuse or bad fuses?

This is at the front driver door

I heard a rattling sound when I would ride over bumps and now the car will not move 5 ft forward or backwards without jumping into gear and refusing to shift upwards to 2nd, 3rd, 4th....gear. It stops every few feet when trying to drive. It is not capable of being driven. This is a 2007 c280 mercedes-benz with 114,000 miles. We are the original owners.

Green light on dash saying brake wear has been on for a week, how soon do i need to get it done and how long can i continue to use car as is??

which color wire is the back up light