2000 Mercedes Benz ML320 central locking/un and panic butto

I found a tech bulliten and it may apply to your vehicle check the VIN and see if yours is in the batch...heres the TSB>
REMOTE CENTRAL LOCKING INOPERATIVE, REMOTE TRANSMITTER LOSES SYNCHRONIZATION TECHNICAL SERVICE BULLETIN Reference Number(s): DTB 03M/00; MB-NET 010, Date of Issue:  January 5, 2000 Related Ref Number(s): DTB 03M/00; MB-NET 010 ARTICLE BEGINNING SUBJECT DEALER TECHNICAL BULLETIN 03M/00 SERVICE INFORMATION 03M/00-2 GROUP 80 - MY 2000, MODEL 163, REMOTE CENTRAL LOCKING INOPERATIVE, REMOTE TRANSMITTER LOSES SYNCHRONIZATION: If you receive complaints, on vehicles within VIN range A145273 to A149599, of the Remote Transmitter Key losing synchronization resulting in inoperative central locking, please take the following steps. 1. First verify that no other faults exist within the system, such as discharged batteries, stuck pushbuttons in the Remote Transmitter. 2. If no other faults are present, replace the AAM2 (N10), located beneath the fuse and relay box in the engine compartment. Note that the new part must be version coded, and the remote transmitter keys must be re-synchronized using Star Diagnosis after the AAM2 is replaced. Also, unlike previous model years, the AAM2 does not carry Drive Authorization information. All parts in PDC stock are of the latest version, having a date code of 419A/B or higher heat stamped into the AAM2 housing near connector 2. Parts Information: 163 545 26 32 AAM2 (N10) WARRANTY INFORMATION Damage Code 82398 52 Operation Code: 54-0000 01 (0.5 Hours) AAM, R & R / Repl. (Includes version coding) © 2008 Mitchell Repair Information Co., LLC. MERCEDES-BENZ: MY 2000, MODEL 163 GROUP: 80 - Central Locking, Infrared Locking Page 1 of 1 REMOTE CENTRAL LOCKING INOPERATIVE, REMOTE TRANSMITTER LOSES ... 3/16/2009 http://www.ondemand5.com/mric/common/asp/printart.aspx

My VIN is much higher - NOW my A/C not blowing cold air. I understand the AAM could still be bad but would that cause problems with the A/C as well as the problem with central locking/un and panic?

I dont think so, but I will pass you on to the MB techs...

The AAM (all activity module) absolutely will cause AC issues as well, as this is where the AC control unit recieves power. Although the campaign listed by merlin does not apply to your vehicle vin range, I have seen issues with these in ML's that are outside of the campaign range. Considering your alarm activity and now the AC not working I would definately gravitate to the AAM as your issue. Since this control module controls power to both of these functions, and it is really your only common component between the two, I personally think this is probably your issue, a failed AAM.

Thanks for the help on the heavy liftin GFI!

Glad I could help