Chevy and GMC Duramax Diesel Forum banner
1 - 1 of 8 Posts

· Registered
1 Posts
The "thud" your talking about in your dash is most likely the a/c pump kicking on and off, it goes on with your defroster too so if you have any of that on you will hear it in the dash and feel it in the floor.
1 - 1 of 8 Posts
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.