As the topic says, my siren is working when it wants. Sometimes it does, sometines id doesn't. Does anybody knows what's wrong with it?

Wow you have siren? You mean horn lol.

Could be the horn itself has got water in .or the connections to horn need cleaning.

Does the horn work off both sides of steering wheel?. If only 1 side is working. The terminals on back steering need cleaning.

I think you have a wiring issue in your steering column since you are also having problems with your windscreen wipers.

I think you have a wiring issue in your steering column since you are also having problems with your windscreen wipers.

Think it could be herbie in disguise

Edited 17 August, 201510 yr by vzo25

I think you have a wiring issue in your steering column since you are also having problems with your windscreen wipers.

Agreed, as long as the OP means "horn" and nor "siren".

 

A "siren" I'd associate with an alarm system, and since there wasn't a factory standard alarm I'm not sure we can diagnose.