Hi. I am an old boy from good old England. Glad to be amongst you.
I don't own a Hummer, but my son-in-law does (and he let me drive it in the desert of Qatar last week).
I would like to find out about a problem he has with his vehicle, if possible.

 

Welcome, do some searching on the forum for an answer to your question. If you have no luck, ask in the section appropriate to your vehicle. Have a great day!