On my 1996 Suburban which is pretty much the same as you're 99. The rear condensor is located at the back door. When you open the door the shelf on the right side is removable. You will see the slots at the end of the carpeted area. That is where the rear condensor is.
Located in front of the radiator on the passenger side in the condensor line.
Located on the lower tube of the condensor, behind the grill on the passenger side.
it is on the inside of the framerail on the passenger side
Your air conditioning condensor is located in front of your radiator
Behind grille , passenger side where the line enters the A/C condensor .
The amplifier is located behind the passenger side glove box.
The heater core on a 1985 Chevy Suburban is located under the dashboard on the passenger side of the vehicle. The glove compartment may have to be removed to access the heater core.
it is on the passenger side conner on the fire wall
It is in the passenger side of the timing cover towards the bottom.
passenger side third spark plug back Driver side ?
The IAC is located on the passenger side of the throttle body toward the rear. It screws into the housing using a 1" wrench.
I believe that it is your oxygen sensor.