Car Alarm - 3g GEMEL made my car a very big paperweight...

[Duncodin]

If anything is shorting then it's likely a switch. That's the only thing that moves.

Do you have a multimeter?

Even if the button feels like it's working the contacts may be stuck closed.

They're usually pretty simple. 4 pins A, B, C and D. Where A-B are usually permanently connected and C-D also permanently connected. Pressing the button bridges them together like this

Can't see in your photo which pins are A, B etc but if all 4 pins are shorted together then you can assume the switch is stuck closed. It might not be as per that diagram but, using a multimeter you should be able to check that the switch actually does something. Contacts open or closed.

Don't have a multimeter? Got an old zed? I'd recommend having a multimeter in your toolbox. They're not expensive.

 

[sqler]

If anything is shorting then it's likely a switch. That's the only thing that moves.

Do you have a multimeter?

Even if the button feels like it's working the contacts may be stuck closed.

They're usually pretty simple. 4 pins A, B, C and D. Where A-B are usually permanently connected and C-D also permanently connected. Pressing the button bridges them together like this

View attachment 327119

Can't see in your photo which pins are A, B etc but if all 4 pins are shorted together then you can assume the switch is stuck closed. It might not be as per that diagram but, using a multimeter you should be able to check that the switch actually does something. Contacts open or closed.

Don't have a multimeter? Got an old zed? I'd recommend having a multimeter in your toolbox. They're not expensive.

Wow, i love this explanation. I have multimeter, literally used it yesterday to find out my alternator in E46 is kaputt

So the 4 pins for the switch are as marked below. I assume i check A with C/D and B with C/D to see if the signal is static. If it is - what are my options? I have a solder but its weak, cannot unsolder this thing....:

 

[Duncodin]

Wow, i love this explanation. I have multimeter, literally used it yesterday to find out my alternator in E46 is kaputt

So the 4 pins for the switch are as marked below. I assume i check A with C/D and B with C/D to see if the signal is static. If it is - what are my options? I have a solder but its weak, cannot unsolder this thing....:
View attachment 327121

In the 4 pins you've circled - assuming that A/B are at the top and B/C below then just but the meter into, what I call, 'beep' mode and touch B and D and if the meter beeps the switch is duff.

 

[ChrisD]

I'm not disagreeing with anything you've been told previously but if you predict trouble with soldering/unsoldering and sourcing an exact replacement you could try extensive use of contact cleaner in and around the switch area. If there is any residue that is causing a short cct it could be anywhere on that cct board. Give it a very good clean and dry before attempting more intrusive operations. Be careful with handling also - static can still be an electronics killer.

Oops - I see you've already been down this route...
As you were.