2006 Jetta TDI limp mode with AC on

New to the forum. I have not seen anything that might explain the problem I am having with my 2006 Jetta tdi, manual trans.

It runs fine until I turn on AC, then it just goes into limp mode.

If am just parked with engine running, turn on the AC - and everything works. Cool air blowing in. Raise the RPM a bit and it just drops it to around 800.

AC is manual temperature adjustment.

Any help would be appreciated.

Update...

Changed alternator along with the belt and high pressure AC sensor. No changes. I will keep hunting.

It'll be easier if you buy or rent VCDS buying more parts. VCDS will show you all the logs and what's triggering
limp mode. It'll also read quite a bit of data for the AC.

When searching, I didn't see much MKV experiences for this issue, but a couple people had similar issues with the MKIV.

http://forums.tdiclub.com/showthread.php?t=421319