In need of a relay.

[93rev2sev]

I would like to build an automatic fuel cutoff switch that can turn the fuel pump on from the drivers seat for theft prevention.

It would disable the fuel pump every time you turn the car off and would require you to press a button or flip a switch to turn it back on when you wanted to start the car...with the key in the "on" position.

I could just use a regular switch (that would be really easy), but I don't want to have to remember to turn the pump off when I get out of the car.

I have a feeling there is a relay that will do just what I'm thinking about, but I don't know relays very well.

I know this has been done before and I'll admit that I have not searched. The only information I need is a model number of a relay that will break when the car is turned off and needs to be reset under power.

 

[93rev2sev]

OK apparently it's called a "Powered, Latching Relay"

Anyone know what I'm talking about?

 

[RickieFrat]

I do. Havn't been in hte SHO game for a bit but know exactly what you are talking about or what to do. I'll try to dig out my books on how to's and repost back to you.

Are you planning on using this only when the car is sitting and not being used?

 

[93rev2sev]

It will be automatic.

Turning the car off will turn off the relay. Turning the car to "run" again will not turn it back on. To turn it back on, you will have to put the ignition in "run", find the relay switch(which I will hide somewhere), and flip it on.

Then you will be able to start it. When you turn off the engine again, the relay gets shut down again...

Automatic. No remembering to "turn off" the fuel pump.

 

[Phoenix]

If this exists , Id be interested in this setup as well , nothing like home made anti-theft.

 

[Toul]

Imo, dont hide the switch, dont have any switch at all, have the relay triggered by something trivial, like the rear defrost switch, or foglight switch, or the in dash volume down button. Something like that.

 

[SHOZ123]

What you need is a pulse latch relay. Wire up what ever you want for the pulse signal then use this diagram to latch it in. When the power is turned off every thing drops out and awaits the pulse signal again to turn on.

 

[Storm-Chaser]

What kind of door switch/relay did they use in the older Continentals and Town Cars, that had the electronic trunk and fuel door release buttons in the driver's door? You could remotely mount one of those in the center console compartment, glove box, or underdash to trigger your relays.

 

[RickieFrat]

Imo, dont hide the switch, dont have any switch at all, have the relay triggered by something trivial, like the rear defrost switch, or foglight switch, or the in dash volume down button. Something like that.

WOW - completely forgot about that. I use to see that allot on the high end cars back in the day when I use to detail them. There was a Range Rover that use to come in all the time for cleaning. In order to start it you'd have to turn the headlights on first in order to start it. Then I remember a Porsche 911 that you had to turn on the heater/AC fans. Very cool idea.