Noticed on my scanner the the alarm is not working  alarm horn h12 no signal/communication

First check the fuse (iircc a 5A) and if that hasn’t gone then it could be the alarm box itself. It could be corrosion to the pcb or the battery itself has gone and/or could have caused corrosion. 

Ta  is the fuse inside?

Yes. 
Are you hearing the alarm blips when locking and unlocking the car. 

Fuse number 35

No sound at all

Fuse still needs checking as no sound still doesn’t really tell you anything 

Where is the fuse  i checked all end of dash and they are all good

Yeah at the end of the dash. 
I would now be looking at the alarm itself. 
It’s under the lining, rear end of the n/s wheel in a metal box, The Easiest way is to remove wheel and lining, remove bolts to alarm box and bend the box down, no need to cut it. 
 

 

Edited 25 June, 20214 yr by Morph

Thankyou pal  il buy one one 

You can cut the alarm open and do a battery replacement if it just that or buy a new or second hand one

When I say no need to cut it I mean the metal box it sits inside as it just bends away but you could carefully cut the alarm open as said and shown above