I'll try and help and sure will be corrected by more experienced on here if required

Leave rear drivers side window open & lock doors with fob (dont dead lock) - indicators should flash
Wait for red running man light to flash on dash
put arm in through open window and alarm should go off -
indicators will flash as hazards if alarm tripped
Alarm sounder should operate
car horn should also operate as well (i think)
if nothing happens then unlock rear door by pulling up tab through window and open the door
this should also enable the alarm as above
If hazard indicators flash and no sound it could be faulty sounder which could have been disconnected by previous owner
If no (hazard) indicator flash at any time or sounder/horn it could be a faulty or disconnected (or even fused) alarm unit.
Dont know location of alarm unit or fuse but bet there is info on here somewhere/someone
Best of luck
