Check the 2005 GMC Envoys turn signal flasher. The flasher could have an intermittent issue causing the signals to not work.
where is the map sensor located on a 2005 gmc envoy
fix for p0123 gmc envoy
what is the spark plug gap for 2005 gmc envoy 4.2l v6
how thick should a front rotor on a 2005 envoy be
Where is the fuel filter located on a 2005 gmc envoy 4x4 4.2
In 2005, GMC recalled 2004 GMC Envoys because of an exterior lighting turn signal problem. According to the company, there was an issue with the signals and lighting malfunctioning when in use.
Usually this tells you that 1 or more lights are burnt out.
25gal
How to change the spark plugs
You probably have a bulb out. Remember, the rear has two blinker bulbs
Subscription run out? Check the fuse.
20 Gallons.