1999 gmc envoySeptember 5, 2014air shocks not working Keywords:air shocksEnvoy 1 thought on “1999 gmc envoy” Freeautomechanic September 8, 2014 at 11:55 am Well why not? just kidding, couldn’t resist. First thing would be to check the fuses and relays. Lucky for us these are also the easiest to access. They are located in the under hood fuse block. So pop the hood and and take a look. Pop the cover off and locate the fuses and relays. The exact location can be viewed in the owners manual(located in the glove box). If you have a message int eh center message center, there will more than likely be a code stored that can be pulled with a scan tool. Comments are closed.