12v Countdown timer, runs a fan for up to 72 hours, resets when Acc supplied.

Hello Circuit Experts!
I am trying to run a small 50mm 12v fan while my car is running, and continues to run from the car battery for up to 72 hours max after I switch off the car. The timer would reset when I start the car again and not start counting down until the car is switched off.
I think this could do it, but I'd like to delay turning off, not turning on?
http://www.ebay.com.au/itm/AC-DC12V...tDomain_15&hash=item5b09292bf4#ht_2806wt_1200

But if it doesn't I'd be capable of soldering it myself, if given a circuit diagram.

Thankyou very much!
Mace

 

The problem is this forum under the terms of service rules prohibits discussion that involves any automotive modifications. There are other forums which will allow these discussions.

Ron

 

I am sure this technically counts as an automotive modification as it's being done in the frame of a car, but for simple electronics, I am using the 12v car battery as a power source and the Acc voltage as a switch.

 

I found this, so will follow up on my query on one of those sites, thankyou
http://forum.allaboutcircuits.com/threads/member-selected-automotive-forums.54400/

Also, the Terms and conditions are hard to find, perhaps the link to them at the bottom of the Forum homepage would be more helpful if named Terms and conditions/of service instead of Disclaimer.
http://www.allaboutcircuits.com/l_tos.html

 

Welcome to the forum.
The owners of All About Circuits has elected not to host discussions of automotive electrical system modifications/enhancements due to safety concerns, the potential of legal ramifications and the possible circumvention of vehicle regulations at the state and federal level.

This thread is against the AAC forum rules, Terms of Service (ToS) :

Any kind of over-unity devices and systems
Automotive modifications
Devices designed to electrocute or shock another person
LEDs to mains
Phone jammers
Rail guns and high-energy projectile devices
Transformer-less power supplies
Terms of Service (ToS)

Automotive modifications of any kind are strictly forbidden. Therefore, this thread will be closed.

Please try to understand the reasons behind this action, and feel free to browse and use the forums.

You might find answers to your questions in one of these forums:

http://forum.allaboutcircuits.com/showthread.php?t=54400

Another good forum that shares many of the same membership is http://www.electro-tech-online.com/ .
This thread will be closed.
Good luck.