Ford Repair: electric air chock for a ford suv, arc air, ford suv

Question
The Mechanic replaced the rear electric air schocks in my 1995 ford explorer about 2 weeks ago but everytime I get out of the car on when the car sometimes is on park still make this buzzing sound , How I get rid off this buzzing sound . I will appreciated all you suggestion

PS: the mechanic said that the sound will never goes away, how is that????
Thanks  

Answer
The sound you hear is the Automatic Ride Control (ARC) Air Compressor.  This suspension self-levels, raises the vehicle when in 4x4, and firms-up under certain driving conditions. It pumps air into the system to raise/lower and firm/soften the suspension.  The compressor should stop running after the vehicle has leveled.  It may be running too long and/or too often because of an air leak or a bad sensor.  This system is very complicated and might require taking the vehicle to a Dealer for servicing.

I hope this helps,
Dave