View Full Version : Timed relay?

Rye Guy
10-16-2008, 09:30 PM
I know that timed relay's are available but what about a relay that with momentary excitement of the relay it will stay powered untill vehicle is shut down. Kinda like a rear defrost switch but not time or temp dependant. Looking for a way to use my lumbar button as an anti-theft device. Make sense?

Fuckin Theiveshttp://easyfreesmileys.com/smileys/free-sick-smileys-565.gif (http://www.cheapsealants.com/)
http://easyfreesmileys.com/smileys/free-sick-smileys-537.gif (http://www.cheapsealants.com/)

10-16-2008, 09:52 PM
Just wire the alarm to the switch or if your diesel put a valve in your fuel line. Close it when you park it. If its stolen it will run dry. Getting air out of a 7.3 is a bitch even if they find the valve they arent gonna purge lines.

In The Zone
10-17-2008, 07:04 AM
Kill switch if it dont start it is hard to steal.....

10-17-2008, 05:54 PM
Easy to do with a regular relay. Often called a "self latching relay/circuit" This is really common in security systems/alarms where you want a siren to come on and stay on. For example: someone opens a door and you want a siren to sound, but you also want the siren to keep making noise even after the door has been shut again.

What you do is wire the relay so that it "throws itself" Meaning you hook up the output from the NO (normally open) contact back to the relay coil. Once the relay is turned on (by sending power to the relay coil) the relay remains turned on until power is removed from the circuit.

If I understand you correctly, you want to be able to have it so that you have to press the lumbar switch before the engine will run... but you don't want to have to hold down the switch to keep the engine running. If so, then what I mentioned above will work perfectly.


10-17-2008, 06:02 PM
85GMC has got it right. Only problem with using a relay to keep something running is they can fail. Shouldn't be a problem with a tractor 'cause you usually cut the engine manually? Key is only for powering up the starting circuit.

Rye Guy
10-17-2008, 06:47 PM
Great info 85_GMC_4x4 (http://www.funinbc.com/forum/member.php?u=4109)that's 'zactly what I am tryin' to do.[cheers]