Yet another alarm question

[Koolflyer]

97 2.8 Roadster with older OEM separate 'brick' alarm control. Last summer my Z3's alarm would start going off randomly I originally thought it might have been the cars battery which was shot, but it has a brand new battery in now, I have changed the 'bricks' internal battery but it still happens from time to time. I have read up on a lot of the posts about this common subject, and can confirm is no water anywhere inside, but I have yet to check the bonnet alarm switch. I'm heard that there might be a battery within the actual alarm siren.....is this correct please? Remember this is 1997 with the 'Brick' not the later built in key buttons. Any ideas?

[Brian H]

The bonnet switch and the radio anti theft switch located behind the radio are culprits for this type of false alarm, I'd try the bonnet switch first though, the bonnet fails to push down the switch enough sometimes, a little spacer or screw on top of the switch will confirm.

Brian

[Koolflyer]

Thanks Brian, that bonnet switch was my next port of call. Also, thinking about it, I had a new radio/CD installed at about the first time it started playing up (last June ish). The Halfords guy had to put a new plug on to fit the new system....that's a possibilty?? Need to see what this anti theft switch and wiring looks like, only had it all out last week! Thank you for that.

[BladeRunner919]

The radio alarm switch isn't part of the wiring to the radio - the original radio has a 'prong' that sticks out of the back and locates in a hole containing a switch. If you have an aftermarket stereo than that switch needs to be disabled, or you need to stick a pen lid in the hole where the prong would originally have located.

[Koolflyer]

Ah righty, tks for that info BladeRunner919, will check that out
Pete KF