01toyotatundra -noise

Truck runs fine. I start truck but turn on ac. I hear like a humming noise ,real low. But it is noticeable. Have had ac in the truck for 1yr. Just got it going yesterday. The noise I can feel the humming. Not really loud. But it seem to be putting strain on the truck. I feel as if the truck runs sort of sluggish and weird when I turn the A.C. on. On top of that the low pitch ,vacuum sound. It sound like the noise you get when you turn when you are low on fluid. It not that loud but sound like that. Can anyone give some suggestions. Please.

 

Ask @LOTSOFTOYS he is a toyota mechanic

 

I'm confused... u added the a/c?

 

No AC was not working. Relay and ac fuse under the hood. Got all the fix and plug the crankshaft sensor back up after I replaced the connector. Got the truck back running and turned on ac it was good. Then I hear this noise like a humming. Almost like a power steering noise. Idk. What you think. Ac and clutch work fine but when I push the button the truck goes in to this struggle mode and the noise

 

Seems like the compressor and clutch is making the noise?