Under the dash
The 2005 Chevy Trailblazer has Coil-On-Plug ignition coils so there are 6 "coil packs". Each one is mounted on top of the spark plug.
Yes.
spark plug
.043
AC Delco iridiums
15mm
Oil pan, bottom of engine. There is a plastic cover over it. Take off the small plastic cover.
Under the left side of dash.
If the car will not start...the spark-plug is bad.
In a 2002 trailblazer it is located on the bottom of the radiator one the passenger side. Every other model year to my knowlege does not have drain plug.
Turn it to the left.
follow the plug wires they are on the heads