When we turn on A.C or defrosters alternator makes noise and vibrates engine drops

If the noise gets worse making a right turn, then goes away or close on a left turn. It is a wheel bearing. If it an engine mount. Put a jack under it and lift the engine slightly. If the vibration goes away. I suggest you replace all the other mounts.

check the engine seat too

There are many possibilities that can cause car to make noise.

It's actually from where the noise is coming from. Front end or rear end. From engine area or from inside the steering or from brakes.

There is N-number of possibilities for the car to make grinding noise or any other kind of noise.

---------

For step by step troubleshooting this problem, I suggest you to refer the help links mentioned below. Its a complete solution with proper explanation to identify the cause of problem: ------

Click the link below: -----

ABS light comes on and Car makes Grinding noise?

http://repairhelpcenter.blogspot.com/2012/01/abs-light-comes-on-and-car-makes.html

------------------

Car makes clicking noise?

http://howtobyme.blogspot.com/2011/11/car-makes-clicking-noise.html

--------------

Car makes whining noise like driving on rough pavement?

http://howtobyme.blogspot.com/2011/12/car-makes-whining-noise-like-driving-on.html

------------

Chirping Noise From Car?

http://technoanswers.blogspot.com/2011/11/chirping-noise-from-car.html

----------------

What are the possibilities for Clicking noise in car?

http://technoanswers.blogspot.com/2011/11/what-are-possibilities-for-clicking.html

--------------

Squealing at start up on car?

http://technoanswers.blogspot.com/2012/01/squealing-at-start-up-on-car.html

--------------

Chirping sound coming from engine?

http://technoanswers.blogspot.in/2012/01/chirping-sound-coming-from-engine.html

-----------

Vehicle making Clunk Thump Thud noise?

http://howtobyme.blogspot.in/2012/03/vehicle-making-clunk-thump-thud-noise.html

------------

4X4 Truck makes roaring noise in the front end?

http://schematicsdiagram.blogspot.com/2012/01/4x4-truck-makes-roaring-noise-in-front.html

--------------

Heater makes clicking noise under dash on Ford Explorer?

http://technoanswers.blogspot.in/2012/01/heater-makes-clicking-noise-under-dash.html

---------------

Clicking noise under dash and front defroster not working?

http://technoanswers.blogspot.com/2012/01/clicking-noise-under-dash-and-front.html

------------------

Car Brakes Making Noise?

http://repairhelpcenter.blogspot.com/2011/12/car-brakes-making-noise.html

---------------

Car Alternator making noise?

http://repairhelpcenter.blogspot.com/2011/11/car-alternator-making-noise.html

-----------------

Car Alternator Bearing Makes Grinding noise?

http://repairhelpcenter.blogspot.com/2011/12/car-alternator-bearing-makes-grinding.html

----------------

Engine makes noise and Cooling Fan belt Breaks?

http://howtobyme.blogspot.com/2011/12/engine-makes-noise-and-cooling-fan-belt.html

--------------

Vehicle Makes Clicking Sound While Taking turns?

http://schematicsdiagram.blogspot.com/2011/12/vehicle-makes-clicking-sound-while.html

-------------

These will help.

Thanks.

There are many possibilities that can cause car to make noise.

It's actually from where the noise is coming from. Front end or rear end. From engine area or from inside the steering or from brakes.

There is N-number of possibilities for the car to make whining noise or any other kind of noise.

---------

For step by step troubleshooting this problem, I suggest you to refer the help links mentioned below. Its a complete solution with proper explanation to identify the cause of problem: ------

Click the link below: -----

Car makes clicking noise?

http://howtobyme.blogspot.com/2011/11/car-makes-clicking-noise.html

--------------

Car makes whining noise like driving on rough pavement?

http://howtobyme.blogspot.com/2011/12/car-makes-whining-noise-like-driving-on.html

------------

Chirping Noise From Car?

http://technoanswers.blogspot.com/2011/11/chirping-noise-from-car.html

----------------

What are the possibilities for Clicking noise in car?

http://technoanswers.blogspot.com/2011/11/what-are-possibilities-for-clicking.html

--------------

Squealing at start up on car?

http://technoanswers.blogspot.com/2012/01/squealing-at-start-up-on-car.html

--------------

Chirping sound coming from engine?

http://technoanswers.blogspot.in/2012/01/chirping-sound-coming-from-engine.html

-----------

Vehicle making Clunk Thump Thud noise?

http://howtobyme.blogspot.in/2012/03/vehicle-making-clunk-thump-thud-noise.html

------------

4X4 Truck makes roaring noise in the front end?

http://schematicsdiagram.blogspot.com/2012/01/4x4-truck-makes-roaring-noise-in-front.html

--------------

Heater makes clicking noise under dash on Ford Explorer?

http://technoanswers.blogspot.in/2012/01/heater-makes-clicking-noise-under-dash.html

---------------

Clicking noise under dash and front defroster not working?

http://technoanswers.blogspot.com/2012/01/clicking-noise-under-dash-and-front.html

------------------

Car Brakes Making Noise?

http://repairhelpcenter.blogspot.com/2011/12/car-brakes-making-noise.html

---------------

Car Alternator making noise?

http://repairhelpcenter.blogspot.com/2011/11/car-alternator-making-noise.html

-----------------

Car Alternator Bearing Makes Grinding noise?

http://repairhelpcenter.blogspot.com/2011/12/car-alternator-bearing-makes-grinding.html

----------------

Engine makes noise and Cooling Fan belt Breaks?

http://howtobyme.blogspot.com/2011/12/engine-makes-noise-and-cooling-fan-belt.html

--------------

Vehicle Makes Clicking Sound While Taking turns?

http://schematicsdiagram.blogspot.com/2011/12/vehicle-makes-clicking-sound-while.html

-------------

ABS light comes on and Car makes Grinding noise?

http://repairhelpcenter.blogspot.com/2012/01/abs-light-comes-on-and-car-makes.html

-----------

These will help.

Thanks.

There are many possibilities that can cause car to make noise.

It's actually from where the noise is coming from. Front end or rear end. From engine area or from inside the steering or from brakes.

There is N-number of possibilities for the car to make wierd noise or any other kind of noise.

---------

For step by step troubleshooting this problem, I suggest you to refer the help links mentioned below. Its a complete solution with proper explanation to identify the cause of problem: ------

Click the link below: -----

Car makes clicking noise?

http://howtobyme.blogspot.com/2011/11/car-makes-clicking-noise.html

--------------

Car makes whining noise like driving on rough pavement?

http://howtobyme.blogspot.com/2011/12/car-makes-whining-noise-like-driving-on.html

------------

Chirping Noise From Car?

http://technoanswers.blogspot.com/2011/11/chirping-noise-from-car.html

----------------

What are the possibilities for Clicking noise in car?

http://technoanswers.blogspot.com/2011/11/what-are-possibilities-for-clicking.html

--------------

Squealing at start up on car?

http://technoanswers.blogspot.com/2012/01/squealing-at-start-up-on-car.html

--------------

Chirping sound coming from engine?

http://technoanswers.blogspot.in/2012/01/chirping-sound-coming-from-engine.html

-----------

Vehicle making Clunk Thump Thud noise?

http://howtobyme.blogspot.in/2012/03/vehicle-making-clunk-thump-thud-noise.html

------------

4X4 Truck makes roaring noise in the front end?

http://schematicsdiagram.blogspot.com/2012/01/4x4-truck-makes-roaring-noise-in-front.html

--------------

Heater makes clicking noise under dash on Ford Explorer?

http://technoanswers.blogspot.in/2012/01/heater-makes-clicking-noise-under-dash.html

---------------

Clicking noise under dash and front defroster not working?

http://technoanswers.blogspot.com/2012/01/clicking-noise-under-dash-and-front.html

------------------

Car Brakes Making Noise?

http://repairhelpcenter.blogspot.com/2011/12/car-brakes-making-noise.html

---------------

Car Alternator making noise?

http://repairhelpcenter.blogspot.com/2011/11/car-alternator-making-noise.html

-----------------

Car Alternator Bearing Makes Grinding noise?

http://repairhelpcenter.blogspot.com/2011/12/car-alternator-bearing-makes-grinding.html

----------------

Engine makes noise and Cooling Fan belt Breaks?

http://howtobyme.blogspot.com/2011/12/engine-makes-noise-and-cooling-fan-belt.html

--------------

Vehicle Makes Clicking Sound While Taking turns?

http://schematicsdiagram.blogspot.com/2011/12/vehicle-makes-clicking-sound-while.html

-------------

ABS light comes on and Car makes Grinding noise?

http://repairhelpcenter.blogspot.com/2012/01/abs-light-comes-on-and-car-makes.html

-----------

These will help.

Thanks.

There are many possibilities that can cause car to make noise.

There is N-number of possibilities for the car to make thud noise or any other kind of noise.

---------

For step by step troubleshooting this problem, I suggest you to refer the help links mentioned below. Its a complete solution with proper explanation to identify the cause of problem: ------

Click the link below: -----

Vehicle making Clunk Thump Thud noise?

http://howtobyme.blogspot.in/2012/03/vehicle-making-clunk-thump-thud-noise.html

------------

Car makes clicking noise?

http://howtobyme.blogspot.com/2011/11/car-makes-clicking-noise.html

--------------

Car makes whining noise like driving on rough pavement?

http://howtobyme.blogspot.com/2011/12/car-makes-whining-noise-like-driving-on.html

------------

Chirping Noise From Car?

http://technoanswers.blogspot.com/2011/11/chirping-noise-from-car.html

----------------

What are the possibilities for Clicking noise in car?

http://technoanswers.blogspot.com/2011/11/what-are-possibilities-for-clicking.html

--------------

Squealing at start up on car?

http://technoanswers.blogspot.com/2012/01/squealing-at-start-up-on-car.html

--------------

Chirping sound coming from engine?

http://technoanswers.blogspot.in/2012/01/chirping-sound-coming-from-engine.html

-----------

4X4 Truck makes roaring noise in the front end?

http://schematicsdiagram.blogspot.com/2012/01/4x4-truck-makes-roaring-noise-in-front.html

--------------

Heater makes clicking noise under dash on Ford Explorer?

http://technoanswers.blogspot.in/2012/01/heater-makes-clicking-noise-under-dash.html

---------------

Clicking noise under dash and front defroster not working?

http://technoanswers.blogspot.com/2012/01/clicking-noise-under-dash-and-front.html

------------------

Car Brakes Making Noise?

http://repairhelpcenter.blogspot.com/2011/12/car-brakes-making-noise.html

---------------

Car Alternator making noise?

http://repairhelpcenter.blogspot.com/2011/11/car-alternator-making-noise.html

-----------------

Car Alternator Bearing Makes Grinding noise?

http://repairhelpcenter.blogspot.com/2011/12/car-alternator-bearing-makes-grinding.html

----------------

Engine makes noise and Cooling Fan belt Breaks?

http://howtobyme.blogspot.com/2011/12/engine-makes-noise-and-cooling-fan-belt.html

--------------

Vehicle Makes Clicking Sound While Taking turns?

http://schematicsdiagram.blogspot.com/2011/12/vehicle-makes-clicking-sound-while.html

-------------

ABS light comes on and Car makes Grinding noise?

http://repairhelpcenter.blogspot.com/2012/01/abs-light-comes-on-and-car-makes.html

-----------

These will help.

Thanks.

There are many possibilities that can cause car to make noise.
Its actually from where the noise is coming from.Front end or rear end.From engine area or from inside from steering or from breaks.

There are N-number of possibilities for the car to make whining noise or any other kind of noise.

---------
For step by step troubleshooting these problem,i suggest you to refer the help links mentioned below.Its a complete solution with proper explanation to identify the cause of problem:------

Click the link below:-----

Car makes clicking noise?

http://howtobyme.blogspot.com/2011/11/car-makes-clicking-noise.html

--------------

Car makes whining noise like driving on rough pavement?

http://howtobyme.blogspot.com/2011/12/car-makes-whining-noise-like-driving-on.html

------------

Chirping Noise From Car?

http://technoanswers.blogspot.com/2011/11/chirping-noise-from-car.html

----------------

What are the possibilities for Clicking noise in car?

http://technoanswers.blogspot.com/2011/11/what-are-possibilities-for-clicking.html

--------------

Squealing at start up on car?

http://technoanswers.blogspot.com/2012/01/squealing-at-start-up-on-car.html

--------------

Chirping sound coming from engine?

http://technoanswers.blogspot.in/2012/01/chirping-sound-coming-from-engine.html

-----------

Vehicle making Clunk Thump Thud noise?

http://howtobyme.blogspot.in/2012/03/vehicle-making-clunk-thump-thud-noise.html

------------

4X4 Truck makes roaring noise in the front end?

http://schematicsdiagram.blogspot.com/2012/01/4x4-truck-makes-roaring-noise-in-front.html

--------------

Heater makes clicking noise under dash on Ford Explorer?

http://technoanswers.blogspot.in/2012/01/heater-makes-clicking-noise-under-dash.html

---------------

Clicking noise under dash and front defroster not working?

http://technoanswers.blogspot.com/2012/01/clicking-noise-under-dash-and-front.html

------------------

Car Brakes Making Noise?

http://repairhelpcenter.blogspot.com/2011/12/car-brakes-making-noise.html

---------------

Car Alternator making noise?

http://repairhelpcenter.blogspot.com/2011/11/car-alternator-making-noise.html

-----------------

Car Alternator Bearing Makes Grinding noise?

http://repairhelpcenter.blogspot.com/2011/12/car-alternator-bearing-makes-grinding.html

----------------

Engine makes noise and Cooling Fan belt Breaks?

http://howtobyme.blogspot.com/2011/12/engine-makes-noise-and-cooling-fan-belt.html

--------------

Vehicle Makes Clicking Sound While Taking turns?

http://schematicsdiagram.blogspot.com/2011/12/vehicle-makes-clicking-sound-while.html

-------------

ABS light comes on and Car makes Grinding noise?

http://repairhelpcenter.blogspot.com/2012/01/abs-light-comes-on-and-car-makes.html

-----------

These will help.

Thanks.

lots of parts, alternator, water pump, a/c compressor lower area . many of them are on the serpentine belt. the pulleys and tensioner can make rattles. you need to confirm which part has the rattle or vibration, use a stick or screw driver. touch one end on the part and the other near your temple...any noise/vibration coming through?

fiind which one it is. lower noise on the crank can also sound like its coming from up front and that's a deep rattle.

a/c compressor may be seized. A/c compressor kicks on when in defrost, a/c, floor/defrost modes any time temperature is above 40 degrees F. That will burn the sepenine belt and stall the engine.
Try turing heat on floor mode only & see if ok.