Battery kill e67

[poulina]

I have an e67/t43 in a custom application.

It has no theft prevention besides door locks/ignition key.

Is there anything wrong with installing a kill switch and cycling often like once a day?

Are there any learned parameters that will be lost in the ecm or tcm by disconnecting battery power? Thanks

[hjtrbo]

There are less brutal ways. A kill switch to the fuel pump achieves the same thing. And it's easier and cheaper to hide than big 'ol battery isolator.

[blindsquirrel]

They (all of them) often have idle issues for a while after a battery disconnect, I would not do it.

Put a simple, cheap toggle switch somewhere easy to reach but not obvious. Wire it between one of the main ECM power feeds and ground. If the ignition is turned to RUN and the switch is not disarmed first, fuse blows (or multiple fuses blow, depending on how devious you want to get).

the evil kill switch.png

You can also build a combination lock with multiple on/off/on switches, and connected so that if they are not all in the right config then the fuse blows.

[Alvin]

I have an e67/t43 in a custom application.

It has no theft prevention besides door locks/ignition key.

Is there anything wrong with installing a kill switch and cycling often like once a day?

Are there any learned parameters that will be lost in the ecm or tcm by disconnecting battery power? Thanks

I've done hidden kill switches on cars that just disable fuel pump, or IGN to the computer, etc.

[blindsquirrel]

But then your added switch has to carry the current of whatever circuit you splice it into. A kill switch that nukes a fuse if not disarmed carries no current unless it is in the process of being stoled and needs to pop the fuse. Otherwise, it sits there and does nothing but be an open circuit.

[blindsquirrel]

Another thing to think about with a conventional disable switch... if teh thief tries to crank it, fails to start, but then finds the hidden switch, it fires up and goes. If there are blown fuses he'll be there for a while. Not many thieves out there carrying test lights and fuse box diagrams.

The only ones I'm worried about are the ones with tow trucks.

[christian moller]

They (all of them) often have idle issues for a while after a battery disconnect, I would not do it.

Put a simple, cheap toggle switch somewhere easy to reach but not obvious. Wire it between one of the main ECM power feeds and ground. If the ignition is turned to RUN and the switch is not disarmed first, fuse blows (or multiple fuses blow, depending on how devious you want to get).

the evil kill switch.png

You can also build a combination lock with multiple on/off/on switches, and connected so that if they are not all in the right config then the fuse blows.

That is a neat solution, the only thing to worry about is as you said, tow truck guy and .........ehhh, my wife.....

[GHuggins]

But then your added switch has to carry the current of whatever circuit you splice it into. A kill switch that nukes a fuse if not disarmed carries no current unless it is in the process of being stoled and needs to pop the fuse. Otherwise, it sits there and does nothing but be an open circuit.

Never dawned to me to try that. That's on another level right there Rig a switch to short the circuit to ground if the key is switched or hot wired and pop a fuse... Of course I would be the one in a hurry or having someone else crank it for me and then I would be replacing fuses, but other than that, pretty smart way to plan that out....

[blindsquirrel]

Yeah but you know which fuse it is and can go right to it. The thief, not so much. They're just going to GTFO and find an easier one down the street.

[poulina]

good info thank you!