I remember a long time ago I ran across a module that would allow post ignition off power so you can roll up your windows and etc and then after the door opening then It kills the power to the battery. Anyone seen this?

 

I've seen this type of device advertised as a way to prevent 'deep discharge' of a battery with a subsequent non-start. Whilst arguably appropriate to an earlier generation of vehicles, they appear unsuitable for modern vehicles which bristle with electronic systems.

Such a power disconnect disables everything, including the vehicle security system making it vulnerable. The further risk is having a locked vehicle which doesn't respond to either the remote or the key.

If a vehicle is to be parked for a lengthy period, a battery tender is a better solution than either an electronic or physical disconnect.

Graham

 

I guess what I am referring to is my wifes ford focus when I take the key out of the iginition the radio and window functions remain on but when the door is opened the power is cut... thats all.

I do not want to do any mods or anything just wanted to maintain power to the battery when the ignition is off prior to opening the doors.

 

How does this work on the Focus - is there some automated switching in the door that cuts the battery off and signals a reconnect next time the door is opened?

Graham

 

No reconnect just a disconnect.

 

I believe my wife's 2008 PT Cruiser does this. I don't know how it works though.

 

Not much help to the X Type owners, but the XK8 is certainly so equipped. The windows and powerfold mirrors can both be operated for about 30 seconds after ignition off. This is achieved by programming within the door modules that are not routinely able to be re configured. However, in the X Type, the powerfold mirrors in non memory, but not memory, cars will still fold after ignition off and the windows (UK and ROW models) can be raised by using 'Global Closing' - press the lock button once to lock, twice to double lock and keep the lock button down until the windows start to move, then release it. Unfortunately, as double locking is not fitted to US models, global closing is not fitted either! It's all controlled in the General Electronic Module (GEM) which is dealer programmable for renewal/exchange purposes, but I doubt the US spec GEM will be programmable for global window closing - it's just different to the UK/ROW spec!. Sorry about that Bracester!

 

I will have to do some more research, I remember one time there was a relay you could install that would delay power shutoff for a few minutes after the ignition was shutoff...

I will find it...

 

Kinda found it: Automotive Time-Delay Relay

Still looking.

 

Found it: Automotive Time-Delay Relay Applications

 

Now to figure out a way to thank myself....

 

The timed relays or event based relays to maintain power inside of vehicles is nothing new. I know the wife's 2006 Chevy Cobalt had this. it is a function that can be activated inside a computer (normally) and how it decides when to turn off is based on how the programmer wanted it. For most cars that have this feature, it is associated with opening the driver's door (or in some, any of the doors). So, you can stop your car, turn it off, yet the windows and radio will remain functional for a period of time. Then the battery saver relay kicks in and forces the accessory (delay) relay to turn off, saving the battery.

If you want his feature inside of the X-Type, you simply need to find the accessory relay that powers what you are after and then figure out how you want to trigger it to remain on and what will trigger it to turn off. This can be done with nothing much more than a bistable 555 timer and a small relay. But, this also requires some understanding of electronics, the ability to solder, and knowing what wires to tap into. There are tons of websites on how to do various things with 555 timers.

In the case of the X-Type, you can trigger the 555 timer to activate with the application of power (ie, turning the car on) using the trigger pin, then use the "door open" switch (this is used to supply a signal to the GEM to turn on the dome light) to turn off the 555 timer since this will ground out (dropping the voltage to 0 VDC on the discharge pin) as the door is opened. If someone is interested in this, let me know. I am sure I can draw up something fairly easy to demonstrate what I am talking about.

 

That website I put on here has a good diagram.