I put my car away in a garage three years ago and the alarm worked fine. Ive bought it back out now and the siren is silent. the immobilizer, door locks, boot pop and indicator flashes all work fine and I can set off the alarm by holding the correct key on the fob, however only the lights flash. can anyone give me any ideas as to what might be wrong with it? It used to be every time I connected up the battery the alarm went off, this no longer happens. I have yet to investigate it, but I haven't moved the car or wiring in that time so i think its unlikely anything has come loose, does the siren have a separate fuse or power, do they ever break and can i get a replacement siren? thanks
The AI606 siren is connected to the alarm control unit through a four-core cable that would be routed through the bulkhead. There are no fuses within this cable, and it is a straight connection from control unit to siren unit. (There is also a bonnet switch wire that exits from it, which should connect to chassis via the bonnet switch when the bonnet is closed. But the state of this will not affect the operation of the alarm in any way.) The four-core cable connects into the back of the siren unit using a small four-pin connector, and it also connects through an inline connector near the panel itself. Therefore there are two sets of connectors there which could be susceptible to moisture and corrosion. I would advise unplugging the connector from the back of the siren and ensure it is all very clean. Actually, tell a lie. Looking at the diagram, there are two separate inline 5A protection fuses that protect two separate permanent positive battery connections to the AI606 system. Both of those fused positive supplies go into the AI606 unit, but the positive supply for the siren taps off one of them. It's quite possible (but I don't actually know) that one of these 5A fuses being blown will kill the siren while the rest of the system stays operational from the other supply. Therefore if you don't get any joy, dig around where the AI606 panel is and check those two inline 5A fuses. However, to save you the hassle of doing this, you could just use a DVM to check that at least one of the pins on the four-pin connector going into the siren has a permanent +12V on it. If the siren itself turns out to be dead then there are cheap replacements on eBay. It may be a matter of buying a generic one that just has a two-wire 12V supply input, in which case you'd want to work out which of the two wires in that four-core cable are the permanent +12V and the one that is switched to 0V during an alarm.
