2004 GMC Envoy. Rear Air lift bags are not inflating. Mechanic says pump needs to be replaced. New pump is $500.00. Any suggestions where to purchase after market product that is not so expensive

Question edited for clarity.
Question moved to model category.

Here are all your fuses

GMC Envoy (2002-2009) fuses and relays

https://fuse-box.info > gmc > gmc-envoy-2002-2009-f...

Here you will find fuse box diagrams of GMC Envoy 2002, 2003, 2004, 2005, 2006, 2007, 2008 and 2009, get information about the location of the fuse panels ...

If you hear a noise near the rear left tire and removing the fuse makes the noise stop, then check the SERVICE PARTS IDENTIFICATION Sticker in the glovebox for code "G67." G67 = Air Level Control suspension, a.k.a. Air Ride Suspension, or Smooth Ride (or Luxury Ride) Suspension. You hear the air compressor turning on/off that inflates the rear air bags; the vehicle does a check when it's started, and will add air when you add weight to the cargo area or add a full load of passengers.

A consumer lawyer has suggested that General Motors Issue a RECALL on these vehicles. Air Bags Problem on the 2002 GMC ENVOY Car problem(s) with the 2002 GMC ENVOY. This database includes information received by NHTSA from consumers either directly or as recorded by the Vehicle Safety Hotline. This information may be used by NHTSA during the investigation process. You may file your own complaint by calling the NHTSA Monday-Friday 8am to 8pm at (888) 327-4236. You can also file a complaint online! Though it has not gotten to the point of them issuing a recall, This is from December, 2014! Hope this helps.

I replace both rear air springs on my envoy denali and it it still wornt inflate all the way up and u could hear the compressor working what can I do to fix the problem

Sounds like the air bag pump went out. I replaced mine and got it on line and saved hundreds. It is located just behind the right rear wheel well just over the muffler.Hope this helps.

well have you determined where the air leak is coming from???? Get soapy water and locate, could just be a fitting loose and a snug with a wrench is all. If this vehicle has an air bag and it is leaking from a puncture or crack in the bag then it has to be replaced, but check air line and fittings with soapy (dish soap ) water first.

I had the same problem with my '02 Envoy 4x4; had the soap test done and there were no leaks; also had the air compressor motor checked and mechanics said it was fine. The rear air bags were worn and cracked so I had them replaced. It lifted and rode at the correct ride height for a few weeks.
After having the rear air bags replaced I noticed that it was starting to not lift as before. Had another diagnostic check; the air compressor was not forcing air through the system in order to lift the vehicle. The air compressor motor was replaced. Compressor comes on and shuts off now.
Vehicle is at the normal ride height now.
Rear air bags and air compressor motor were dealership parts; unable to find after market; not recommended to replace with used parts.
I had the dealership to run the diagnostics and had another mechanic to replace the parts. Total repair for bags, motor + labor = $1500

check the air compressor for the air bag should be around the top of engine

Just behind right rear tire up in the wheel well. Air inlet is inside right rear quarter near the accessory inflator. Compressor runs 3 lines one for the accessory inflator and one for each air bag.
THere are also 2 sensors, one on each trailing arm that senses load and then raises and lowers accordingly.

over inflated
will not go back to normal level