I would say, underside of the passenger side dashboard. Yea, that is what you would be looking at...............
Sorry I could not resist. Welcome aboard! You question will get more attention in the appropriate technical forum. This is the new members forum where you introduce yourself, post some pictures or tell folks where you live. You can encounter smart a$$es like me in just about any forum.
I have no experience with the Envoy but I have heard it can be done on the older K series trucks though it is not particularly easy job. My factory manuals show literally removing the dash from the 98 chevy trucks to do the job. Since there are guys who have done it before without pulling the dash, a factory manual may not provide the simplest way to tackle the problem. Good Luck
A forum community dedicated to all General Motors truck owners and enthusiasts. Come join the discussion about performance, lift kits, wheels, tires, modifications, troubleshooting, maintenance, and more!