View Full Version : Kill Switch

17-10-06, 15:33
in my car i still got a problem that drains the battery when the car is off and was wondering wether i should put a kill switch that will only allow the alarm to operate while the car is off. is this possible and if so, can someone do a tutorial with pics and instructions, cheerz in advance.

17-10-06, 20:22
Its highly unlikely that the car alarm would be able to drain a fully charged battery that is in good condition over night or even over a period of weeks. Alarms and immobilisers draw extremely low levels of current. And using a switch to activate the alarm whilst the car is off is pointless as firstly when the car is running the car generates its own power through the alternator and the battery becomes a load like everything else.

Have you recently added anything electrical to your car? Amp's are a good example!

Is your battery in good condition? Poor condition batterys will often drain themselves of power over a few nights even without an additional load.

Finally is your alternator actually charging the battery? To check this disconnect the coil and crank the engine over a few times.
Now reconnect the ignition coil and place a volt meter over the battery terminals, it should read between 12 and 13 volts, now start the car, the voltage should raise to 14.8 volts or close to this figure. Turn on the headlights, sterio, aircon on high to create a load, does the volt meter still read about 14.4 - 14.8 volts? give the car a few revs the voltage should increase slightly but not go over 15v.

If this is all good then your alternator is fine and is charging the battery.