I have a 2004 F150 with a Ford brand, dealer installed (I believe it is a Code Alarm) remote start/truck alarm. The siren recently started sounding off constantly without interruption. It does not matter if the truck is running or not, or if the alarm is armed or not. However the siren is only at about 5% volume level.

If I intentionally trigger the alarm, only the horn sounds, not the siren (the low volume siren may be sounding but I cannot hear it over the horn blasts)

Would you have any idea what could be the problem? I know it is a hard question without seeing it.

Thanks in advance,
mikebaby