I am not too familiar with this site, & ain't sure of my posts are posting in the right area to be responded back to. Also, I have a lil' hard time to find my post to view any feedback.

I have another problem: I was told to change my rear shocks (which I did) Now, I don't hear the compressor. As I recall, I think it went out before the shocks were replaced. I searched the internet and read somethings about switch & fuses. Do you think possibly, one of these were my problem in the first place? I also have noticed my rear no longer rises. I do hear a noise near the passenger rear tire. How can I tell if my shocks are getting filled with air? By the way, (embarrassed) Where is the air compressor located and a switch, fuses? Thank U so kindly

When you had the rear shocks changed, did they use air shocks? They may not have. The compressor is located behind the right rear wheel well under the car. I'm guessing they didn't use air shocks, or failed to connect the air lines.

Welcome to GM Forum. I moved your thread into the Bonneville Mechanical & Maintenance section; General Chat is just for… well, general chat. Don't worry about it.

Yes, I got the air shocks, I do hear a noise near the rear passenger side tire. However, before I use to hear it kick in every now n' then... then heard nothing... then got the air shocks changed, but now I don't hear anything kick in at all.
I am also having some vibrations when I am driving at about 90km, then when I have to slow down, the vibrations are felt thru the steering wheel. Also, I can feel it when I am traveling about 40km, there is slight vibrations.
I did change 3 of the tires.However, the two front tires had wear on the outer side, whereas, the rear driver side tire had wear on the inner side of the tires.When I took rear tire off, it had lumps on the inner side. My friend told me he feels lumps on the other rear tire.
Some things that have been changed are, the outer tie-rod (driver side), control arm (passenger side) 3 of 4 of the tires (so far) rotors, pads & rear air shocks.
I brought it to the garage for an inspection now, they are telling me I need to change the strut mounts (quick assembly kit).Can the strut mount cause vibrations? The thing is I am weary because they told me I need to change the control arm, which I did... but, it didn't stop the vibrations & they dinged me for 325.00 Cdn. Plus, they been telling me to change the rotors, tires, shocks etc. Do ya' think, I should get a second opinion before I get the strut mounts changed?
Do ya' think all I need is an wheel alignment?

bad shocks and struts cause the tires to wear in a way that makes a bunch of vibration and noise like you say, why would you change 3 tires instead of 4? that one could be making noise too.

i would get the other tire, front struts ( they wear at the same rate as the rears) mounts, and an alignment ( that should have been done with the other work that was done) that should stop your uneven tire wear.

if its still makes the noise it could be wheel bearings

Ohh, the reason why I only got 3 of 4 of the tires changed was because due to being a weekend (Saturday) There was no stores open to buy any tires, the ones I bought were off a friend, plus this past weekend was a long weekend for both the Canadians & Americans. I had to wait till Monday to purchase another tire.
I did buy another tire & got all tires properly balanced. Took it for a test run and found it no-longer vibrated nor it pulled to the right at any speed. However, when I pressed on the brakes, I had some vibrations and the mechanic figured it was due to a bad rotor (rear) To make a long story short, I stated to him, when my friend previously changed the back rotors the caliper stayed stuck when I took it for a test run, and they were smoking and my friend poured water on em' to cool em' down. The mechanic figured the rotors warped and told me to try to put the old rotors back on to check if it will continue to vibrate. (he feels this is the cause of the vibration) I do know I have to eventually change the strut mounts, very costly...lol
I will post if all of the vibrations will no longer vibrate when I change the rear rotors.
Word of wisdom, one of the important things to maintain a vehicle is to have all tires properly balanced and to have an wheel alignment done, it will save a lot of headaches down the road.

the compressor should come on a little after startup and run maybe 2-5 seconds. This is to just check the level etc and confirm it works. If the shocks and lines are well sealed, then there is no need for the compressor to run unless a load has been added.

Get two friends and turn the car on with the trunk open. Then sit on the trunk edge to simulate a load in the truck. In about a minute the compressor should kick on and raise the back end.