I am looking for more than a yes/no answer.
The inside of my security siren sports the usual dark and mucky circuit board, from battery damage.
1 Is there a chance it may still be good, and need a cleaning? With what chemical?
2 But mostly, I am looking for a work-around the siren. I have heard that it was tied into the sunroof controls (I am having trouble there, with the sunroof not closing.) Is it necessary for other parts of the car?
3 The siren unit appears to me to be more than a RESPONSIVE device. If it simply responded to security issues, then it could simply have an electronic switch and amplifier and tone generator and speaker. Its board looks much smarter than that. What does it do?
4 There are just three leads into the device. Which is which? and would it help to tie two of them together with a jumper, to make the rest of the car "happy"? If so, then which lead is which?
I'd be delighted to get an informed answer on this.
Revmarkruppert

 

You can disconnect it. You'll have an Alarm System Service Required message. If you want that gone, the dealer can download software to remove the alarm from the car configuration.

 

es6t,
Thanks for the response. I did remove the broken siren,, and shortly thereafter my sunroof problem popped up (unable to close.) Now that could be its own problem.
A nearby Volvo service manager told me on phone that there is a connection betw. siren and sunroof. He told me of a reset to enable closing roof: Start engine, then hold sunroof button forward for abt. two minutes.
That did not work for me.
For now, a tarp is keeping the rain out- mostly.
Mark R

 

Yes, the siren and sunroof are on a network together. If the siren battery fails, the sunroof will still work. However, sometimes the siren actually shorts the network, causing the sunroff to also not work (same with keyless entry). But in all cases I've encountered, simply unplugging the siren (and this removing the short) allows the rest of the network to operate normally.