Including but not limited to Escalades, Hummer and full size vans a common and growing problem with automatic A/C blowers not functioning properly. You could turn the key off and remove and the blower may stay on. The A/C is on but no air movement, or the fan operates randomly.
Fortunately the fix is simple, usually it's a small control module that cost between $50 to nearly $100 depending on name brand Vs generic replacements. The blower control module is located under a hush cover below the glovebox on the passenger side. Two 7 mm screws to lower the hush cover enough and 2 5.5 mm screws attaching the module. Releasing the plug in wire harness (2), can be a frustration and splicing wires reusing the original plug-ins will be the only hang up to an otherwise 10 minute fix. One important word that repair manuals don't explain - Don't disconnect the battery for this job. Instead remove the 40 amp fuse labeled DWLR located in the fuse terminal box located just forward of the master cylinder on the left fender. If you disconnect the battery during this repair the computer will like relearn a secondary run procedure and you will then need to shut down the A/C prior to removing the key and start the engine with the A/C off each time or you may/will damage the new module.
This has yet to become a recall (despite the fact that 3 in 5 involved vehicles will have this problem develop) because it is not a "safety" concern. However, a disabled windshield defogger is a safety issue and this subject is scheduled for a hearing this fall at the Federal Highway Administration.
I hope this helps someone.
Fortunately the fix is simple, usually it's a small control module that cost between $50 to nearly $100 depending on name brand Vs generic replacements. The blower control module is located under a hush cover below the glovebox on the passenger side. Two 7 mm screws to lower the hush cover enough and 2 5.5 mm screws attaching the module. Releasing the plug in wire harness (2), can be a frustration and splicing wires reusing the original plug-ins will be the only hang up to an otherwise 10 minute fix. One important word that repair manuals don't explain - Don't disconnect the battery for this job. Instead remove the 40 amp fuse labeled DWLR located in the fuse terminal box located just forward of the master cylinder on the left fender. If you disconnect the battery during this repair the computer will like relearn a secondary run procedure and you will then need to shut down the A/C prior to removing the key and start the engine with the A/C off each time or you may/will damage the new module.
This has yet to become a recall (despite the fact that 3 in 5 involved vehicles will have this problem develop) because it is not a "safety" concern. However, a disabled windshield defogger is a safety issue and this subject is scheduled for a hearing this fall at the Federal Highway Administration.
I hope this helps someone.