Duplicating duff battery effect - vehicle security

[rtbcomp]

Many years ago a contributor to practical electronics came up with a circuit which cut the feed to the coil randomly. Theory was the car would start as normal but keep cutting out/resetting randomly giving the thief the feeling the car was faulty. He was confident that even if the car was stolen, it would be abandoned within half a mile. Probably quite difficult to achieve with modern electronics but the thinking was sound.
RonA

You could probably do it with a software patch in the ECU these days.

The problem with devices that let you crank the engine is that chummy could leave you with a flat battery, the headlamp bulb method gives the illusion that the battery is flat, but in reality it isn't.

 

[Olderisbetter]

Just buy a Renault they have plenty of random electrical things going on that could easily make you think the car is undriveable.

 

[Migmac]

Something like this!

Can you imagine the christmas tree of lights that would appear on the dash if you did that now?

Misfire, coil pack fault, emissions system fault, "stop" light because of risk of damage to catalyst, lambda fault/damage.

After the first activation, it'd almost certainly go into limp mode if it runs at all.

 

[Hood]

Just buy a Renault they have plenty of random electrical things going on that could easily make you think the car is undriveable.

I know all about that, had a Megane 1.9 Estate, great car apart from the electrics, always seemed to want to go into limp mode just as I was overtaking
Never could find the problem, diagnostics never had a fault code. Add to that doors locking/unlocking on their own, indicators sometimes working and other times not plus lots more weird things. Liked the car and was loathe to get rid of it but in the end I had had enough so just scrapped it.

 

[Olderisbetter]

I know all about that, had a Megane 1.9 Estate, great car apart from the electrics, always seemed to want to go into limp mode just as I was overtaking
Never could find the problem, diagnostics never had a fault code. Add to that doors locking/unlocking on their own, indicators sometimes working and other times not plus lots more weird things. Liked the car and was loathe to get rid of it but in the end I had had enough so just scrapped it.

My mate had one we would fix very few weeks 5 years old and you could indicate and it would have a break down as soon as the indicator cancelled, Leather trim nice car just so many electrical issues, like the electric window at the back went down randomly on its own.

 

[Hood]

.... like the electric window at the back went down randomly on its own.

Had that as well, also front ones would sometimes not go up until you switched off the ignition and turned it back on.

 

[rtbcomp]

^^ That's typical of Windows

 

[KemppiFrog]

Talking of Renaults My Espace has a bypass on the fuel shut off valve (Diesel) as when I swopped the injection pump the replacement didn't have the anti theft system. So all I need is to fit a concealed switch (instead of twisting two wires together) and Bingo! Though the chances of anybody wanting it are pretty slim.