Hi guys. Need some help please. I`ve got the car stood outside the house not being driven and when the battery goes flat off goes the alarm! Can anyone tell me tell me how to disable/disconnect the alarm please. Also is there a way of stopping the interior lights coming on as this obviously drains the battery before I can start it up n off goes the alarm! Thank you. John ...Also, I nearly forgot. Anyone any ideas how water keeps getting under the battery every time it rains? It`s like a swimming pool?? Thanks again

 

Firstly, what is the battery voltage across the terminals with the ignition in the OFF position for ten minutes, or longer? There should be a minimum of 12.6 volts across the terminals, if not, charge the battery overnight at 5 to 10 amps and retest. If voltage is still below 12.6 volts, the battery is suspect and should be replaced.

Water in the boot can cause many electrical issues to arise, as will a failing or weak battery. Check the moon roof drains to ensure they're open and drain properly, then check sealing of the boot seal and tail lamps. If the rear window (backlight) has been replaced, check to see it's properly sealed.

 

You live in England, right? Your car is probably equipped with a secondary alarm system, known as the passive sounder. The main alarm runs off the car's regular battery and sounds the car horn and flashes the lights if triggered. Are you getting the flashing lights when the alarm sounds?

If the main battery goes dead (which yours is apparently doing), the passive sounder kicks in. It has its own dedicated battery built into the unit, hidden under the fuse panel by the engine. It makes its own siren noise, but IIRC, does not flash the lights or sound the car horn. Lots more details at this link:

https://www.jaguarforums.com/forum/s...02-how-189612/





Definitely fix the water leak. This is probably the root cause of all the problems with the battery discharge, alarm, and interior lights. The electronic modules back there are acting up due to getting wet. Check out this thread for more info:

https://www.jaguarforums.com/forum/s...ng-trunk-7798/


Specifically, see post #35 for Gus' experience with water leaking at the tail lights.

See post #42 for my experience with the trunk seal. I replaced that and didn't touch anything else. Voila, no more leaks.

The tail lights and the trunk seal appear to be the two main causes.

 

The alarm is to stop theft and is deliberately therefore made hard to disconnect.

Probably a lot easier is to fix the leak and keep the battery charged.