I have been searching the a/c threads and cannot find one with the same thing mine is doing.

a/c is blowing air fine, but not cold. when i start the truck and turn the a/c on, about 3-5 seconds into it i feel a thump in the floorboard. kinda like someone hit the truck with their fist.

Just had the condenser replaced about two months ago, now this.

Again, its blowing air, but not cold air.

wanted to check with the group before calling the dealership.

 

The thump is most likely the clutch trying to engage on the compressor. Have someone hit the A/C button while you watch the compressor. Mine did the same thing and you might notice the clutch trying to engage several times and then stop. I fixed mine with a new clutch from eBay.

 

I know the sound you're hearing....it's hard to pinpoint, but on my '03 it use to make the same sound. I thought at one time it was the door in the a/c plenum flopping back and forth but once it failed completely it then sounded like it was coming from the firewall.....kinda like there was a "concussion in the dryer"......sounds goofy but that's the best I can describe it. I ended up replacing my a/c system a few years ago and I have never heard it since.