Could be a SCU relay? Check Technozon posts he has a massive FAQ and is the 'don' in this area.

Im sending mine to him to be overhauled in January

 

thanks for the reply.
scu would be pektron cars, right?
mines an '02 with the lucas fob

 

Ah right, im not 100% then. Sounds like an MOT failure though! Sure someone brither than me will be along soon! Possibly boot wiring issue. but thats a guess at best.

 

Run a wire from the + terminal on the horn and touch it on the positive terminal on the battery. If the horn sounds then it is OK.

 

ill try and find some to do that.
i thought that even though the horns dont work, the alarm should still flash the indicators when triggered?
the indicators flash when armed and disarmed, but i can open the bonnet etc without any lights flashing.
just hoping that its something simple. dont mind changing the horns if needs be, but the alarm not working is....bleh

 

just tested one of the horns by wiring it directly to the battery and it works. so the fault is somewhere else

 

so it gets weirder (or possibly easier).

sat in the car, locked/armed it with the fob, then tried to start it and the alarm went off (its quite loud, wasnt expecting that).
so the horns work, they get power, but the horn buttons dont work, so thatd be the airbag squib/rotary coupler then?

seems strange how the alarm wont go off if im sitting in it making noise or open the bonnet, but it does if i try to start it.

 

Opening the boot with the key disables the alarm in the boot section. A faulty bonnet switch will stop the alarm sounding when the bonnet is opened, and if you have a 115 then you won't have an interior microwave sensor (or that could be faulty too).

open the driver's window and then set the alarm but don't deadlock it. Try and unlock and open the driver's door. The alarm should sound.

As regards the horn buttons, that more then most likely is the rotary coupler, yes.

 

Its a 160, but can't see any sensors in the cabin. Guessing they're an option, as the manual says ` if fitted`?
I'll try and get a new bonnet switch, see if that makes a change, and try the door unlock asap.
Thanks

 

The sensor is behind the T bar. It's a cream box.

 

tried out your method of opening the door, and it worked. also tried with the window down and stuck my head in, also worked.
tried with the bonnet up, but holding down the switch, and released the switch to a loud noise! so the alarms fine.

then tried apttony's method for jumping the pins behind the coupler (http://www.apttony.co.uk/Servicing/HornFailure.html) and the horn worked, so its definitely either the steering wheel buttons or the coupler.

thanks a lot for all the help guys