Driving the car yesterday and suddenly the alarm went off. Stopped and reset and it was fine. Then parked up UNLOCKED and off it went again. Left overnight with no problems. 3pm this afternoon having been sat locked all day the alarm triggered again. Now when I lock and unlock there is a distorted chirrup sound from under the front scuttle moulding. Assuming this is the siren but it's never done it before
any ideas guys???

 

Remove the front scuttle and unplug the siren, it's batteries have ruptured and corroded the circuit board.
You can order a new one for a slk320 or sl32 amg

 

Beeping sirens CLICK.
Replacing batteries in the siren if no leakage damage. CLICK

 

Is there a video somewhere of how to replace the alarm?

 

It is not difficult. Once you achieve access, there is only one small bolt holding it in if I remember correctly. I had the crickets on crack symptoms and removed my alarm and performed a battery replacement which required splitting the alarm speaker and regluing it after battery replacement. Good luck.

 

Removed my alarm siren today. Saw how to take it apart and replace the batteries. Where is a good place to buy the batteries are replace the siren with one with new batteries
thanks