anti-hijack

Printed From: the12volt.com
Forum Name: Car Security and Convenience
Forum Discription: Car Alarms, Keyless Entries, Remote Starters, Immobilizer Bypasses, Sensors, Door Locks, Window Modules, Heated Mirrors, Heated Seats, etc.
URL: https://www.the12volt.com/installbay/forum_posts.asp?tid=82091
Printed Date: May 02, 2024 at 8:32 PM

Topic: anti-hijack

Posted By: madal
Subject: anti-hijack
Date Posted: August 26, 2006 at 7:55 PM

Hi. I'm trying to make an anti-hijack system for a diesel van. Needs to hold power to the fuel pump solenoid when the keys are removed from the ignition so vehicle battery will remain charging, but don't want anyone to be able to drive off!!

I know some systems are available, but there must be a cheaper way! I've taken a couple of circuits and combined / modified them, would just really appreciate anyone looking over my plan and giving any suggestions. Or pointing out any faults! :)

posted_image

Vehicle will be left WITHOUT keys in, and if i've done it right, will cut out (with no restart capability) if clutch or brake pressed or handbrake released.

One last thing. I know it may not be legal, or insurance approved, but hey, needs must.

Thanks.

Replies:

Posted By: iskidoo
Date Posted: August 27, 2006 at 1:27 PM

That seems pretty complex for what you're trying to achieve. Why not just use a simple toggle switch that turns on a relay to power the igniton wire. (Unless the ignition wire doesn't provide power to the fuel pump.) When the engine is already running you flip the switch and the ignition remains powered through the relay. You turn off the key and remove it which should lock the steering wheel. For added safety you can feed the ground input of the relay (pin 85) with a negative from the parking brake and/or clutch switch as you've shown in your diagram. The switch can fused +12v and when turned on provide the relay (pin 86) with power to turn it on.

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Steve G

Posted By: auex
Date Posted: August 27, 2006 at 3:36 PM

So how do you shift or turn the wheel if the key is out and they are locked? Too complicated.

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Certified Security Specialist
Always check info with a digital multimeter.
I promise to be good.
Tell Darwin I sent you.

I've been sick lately, sorry I won't be on much.

Posted By: iskidoo
Date Posted: August 27, 2006 at 3:39 PM

auex] wrote:

So how do you shift or turn the wheel if the key is out and they are locked? Too complicated.

Why would he want to, the vehicle is unattended.

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Steve G

Posted By: ck auto
Date Posted: August 27, 2006 at 5:34 PM

why not use a remote car starter and tie in the overheat light to hood pin to shut down if over heat simpler and almost same cost as 6 relays for a cheap starter and a lot cleaner looking

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good luck
kirk

Posted By: iskidoo
Date Posted: August 27, 2006 at 5:36 PM

What is this for anyway. What vehicles are you wanting to leave running unattended? Delivery, refrigeration, maintenance at a troubled youth center?

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Steve G

Posted By: auex
Date Posted: August 27, 2006 at 5:39 PM

iskidoo wrote:

auex] wrote:

So how do you shift or turn the wheel if the key is out and they are locked? Too complicated.

Why would he want to, the vehicle is unattended.

I know, the circuit he designed isn't really needed seeing how no one can drive off with it.

-------------
Certified Security Specialist
Always check info with a digital multimeter.
I promise to be good.
Tell Darwin I sent you.

I've been sick lately, sorry I won't be on much.

Posted By: madal
Date Posted: August 30, 2006 at 3:21 PM

Thanks for the input, and yes, i realise it could be done easier. But i'm trying to utilise the momentary switch and L.E.D. that were fitted to the dash previously and are now redundant, save drilling more holes. I appreciate that would get rid of the need for 4 relays!

Its on a breakdown recovery vehicle, which needs to be left unattended sometimes but running to keep all the lights and warnings going, but some other firms locally have had their vehicles stolen, hence the over-kill.

Again, thanks for time to help. posted_image

Posted By: iskidoo
Date Posted: August 30, 2006 at 4:33 PM

Just put the toggle switch in the place of the momentary and I guess you can utilize the LED if you like.

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Steve G