The 2002 Chevrolet Trailblazer air pump can be found on the firewall in the engine compartment. The air pump will be on the passenger side of the firewall.
the air pump on 2005 trailblazer is located on the frame rail on the drivers side .by the drivers door
If the air vents of the Chevy trailblazer 2004 are not blowing air, have the fuel pump checked.
The 2006 did not have one.
Probably not the air pump. Could be the power steering pump or the tensioner pulley or maybe the idler pulley.
The secondary air pump is located on the passenger side of the engine near the top sticking out of the side.
Secondary air injection malfunction. Maybe the air pump failure or a leak?
On the fluid reserve tank under air filter.
see "how too replace water pump on 2002 Trailblazer"
The torque of a water pump bolt can be requested from the manufacturer. The Chevy Trailblazer has a high torque for the water pump bolt.
In the fuel tank
If your Chevy trailblazer 2004 gauges are not working, check your fuel pump.