2003 explorer xlt with 103k. There is a thumping noise in back interior quarter panel behind interior trim. Took rear panel and checked rear a/c fan and that’s not it. The “tone” of the thumping changes when you turn a/c on compared to off but regardless it’s still there and in the same general area. Any ideas, I’ve never experienced this before!
In addition to the blower motor back there , there are two blend door motors. It’s probably one of those having trouble that you’re hearing.