[muttsjet]

2002 Esprit - Optima battery static charge 12.7

Out of the clear blue sky, alarm siren started bellowing regularly until I disconnected the battery. Read thru all the alarm siren related threads. Threads seemed to indicate that a bad battery could cause this problem. However, as best I can tell, the battery tests ok. Would a bad battery in the siren cause this to occur?

Where is the siren located in relation to the fuses, relays, OBD port under the right quarter panel?

Thanx.

 

[tmusc]

you have to take off the right rear filler piece under the right rear quarter window. The module and the siren is located there.

 

[jtrealty]

The siren does have it's own battery. If it is NG you will have to cut it out and find a replacement that can fit. The fact that the noise stopped when you disconnected the big battery means the battery inside the siren module is dead. It should have kept going with the big battery disconnected. It is a Ni-Cad battery that gets charged off the big battery and the motor when it is running. Most likely original and is 17 years old. Way past the "best till" date.

 

[muttsjet]

Thanx for the inputs. Can I assume the reason the siren started going off for no reason is that the siren battery failed? Or, is there another problem (ie, a fuse that may have caused it to go off in the first place)? If a fuse, where are the alarm fuses located to check?

 

[jtrealty]

The bad battery caused the alarm. If a new battery doesn't fix it you will have to find a siren module because it is also defective.

 

[Add Lightness]

I actually had a bad battery ruin the internal circuitry of the siren module by leaking battery acid on the board (not uncommon). The battery is very easy to remove after getting the siren out: just remove the screws from the case and unplug the battery.

After buying a replacement, I modified it to avoid the problem. You can just drill a hole in the plastic case large enough for the wire to go through, and externally mount the battery. I just used electrical tape to wrap the battery around the outside of the module, and while it looks a bit “sloppy” it’s not like anyone can see it when it’s installed.

Jake

 

[muttsjet]

Most helpful replies. Am on it. Thanx.