A/C not working on Low Fan

[DTJ9610]

We have a 2011 Laredo 303TG. I have noticed that our A/C doesnt't want to work on the low fan setting, only high. This has been going on for about a year now. We were out 4th of July week and it started to work on low again, however then noticed a crazy loud (for lack of a better description) thumping/banging noise. At first is sounded like someone was pumping out or tank, until I realized it was coming from the A/C Unit. Turned it off for a bit and now it's back to only working on high fan setting. Not sure i anyone else has had this issue before.

[scrnt]

When we purchased our cougar the tech that was helping us with everthing told us not to run our a/c unless the fan was on high. We live in the south and he said on low the a/c can't keep from freezing up on the low setting. We have keep it on high and no issues.

[labs4life]

Same thing was told to me. I am also in the South.