Bat Flattery trouble

[thefox3305]

The missus left the ignition and interior lights on in her Mondeo hatch Sunday.

Flat battery this morning. Voltmeter showed 2.7 volts.

I hooked up the jumper leads to xr6, and had it ticking over for a while. Turned off, disconnected. 11.7 volts, should be enough? Give it a go.

All dash lights worked, but no attempt at spinning motor. Nothing. Message on screen: Immobiliser Active.

Paniced a bit. Had i damaged something? Had not tried to start with jumper leads. Book no help.

Try other key. Same thing.

Drop into local dealer. Helpful, but no suggestions other than"they don't like jump starting", which i hadn't done.

Long story short. Had to disconnect the Mondeo battery completely, leave it disconnected for quite a while (i tried 10 minutes, didn't work. 2 hours did.) Charge the battery to over 12.5 volts. Reconnect. Started first go. Both keys recognised. Immobiliser must have reset itself.

No security code request from stereo, which i though was odd but i haven't checked what the manual says. Clock time and bluetooth pairing gone. Other than that, no hassles. But you wouldn't want to be in a hurry to get going.

Trevor

[MaTTe]

hey mate, connecting jumper leads to a car is the same as jump starting it.. cars with computers dont like it, unless you have the jumper leads with the earth leakback wire(or whatever they call it), its a small wire the connects to the earth on one end.

Car batteries generally hold 14V odd.. so 12V is about where you'd want it to be, i would have taken the car for a drive rather than having it sitting with jumper leads on as it will run the car off the alternator and charge it as it goes.

The cars don't always need a code for the stereo unless you go disconnecting components, they usually have enough residual charge in the system to keep the codes in memory.. this is not always the case, but in general terms.

[apstar]

I have a cigarette lighter plug that I modified with a diode to prevent voltage coming back to a 9v battery on the other end of the plug,works a treat even mates come to borrow it when they change batteries keeps the CPU[no need to relearn ] and radio code up while the battery is changed

apstar

[NZ XR6]

The Mondeo handbook has instructions on jump starting. So as long as you use the right leads with the thingy to prevent voltage spikes all should be sweet.

With a dead flat battery I'd suggest it's always better to use a charger to bring it back to life. Or if this isn't an option, take it for a long drive (1 hour) before trying to restart it.

But I don't understand what happened with your immobiliser. Could be very scary if it happened in the wrong place at the wrong time.