The 1947 - Present Chevrolet & GMC Truck Message Board Network







Register or Log In To remove these advertisements.

Go Back   The 1947 - Present Chevrolet & GMC Truck Message Board Network > General Truck Forums > Electrical

Web 67-72chevytrucks.com


Reply
 
Thread Tools Display Modes
Old 08-13-2012, 04:23 PM   #1
THE "10" SILVERADO
Registered User
 
THE "10" SILVERADO's Avatar
 
Join Date: Sep 2010
Location: Marble Falls, TX
Posts: 1,575
Relay Question?

I'm putting an ignition kill switch in my truck (along with another switch on the NSS) but I've got a question about which relay to use.

For the ignition I don't want to use a Bosch style because if the switch accidentally turns off while I'm driving it will still kill the coil power, what kind of relay can I put in that would cut power when the switch is off but after the car is started (ignition on) would stay on even if the switch turns off? So say if I hit a bump and the switch malfunctions it would stay running and only turn off when I killed the engine (killing the engine would work like a reset button or something). I'm sure there is something like that out there but I don't know what it would be called to get it.

Thanks
Michael
__________________
Michael
Re-starting the neglected '77...http://67-72chevytrucks.com/vboard/s...=425464&page=9
THE "10" SILVERADO is offline   Reply With Quote
Old 08-13-2012, 05:46 PM   #2
FLEET72
Registered User
 
FLEET72's Avatar
 
Join Date: Jan 2007
Location: Sonoma, CA
Posts: 521
Re: Relay Question?

Try here http://www.the12volt.com/relays/page2.asp
__________________
Oscar
'72 Shortbed Fleetside
'95 Jimmy 4X4
'69 GMC Custom Camper
FLEET72 is offline   Reply With Quote
Old 08-13-2012, 10:37 PM   #3
THE "10" SILVERADO
Registered User
 
THE "10" SILVERADO's Avatar
 
Join Date: Sep 2010
Location: Marble Falls, TX
Posts: 1,575
Re: Relay Question?

Thanks for the reply but that confused me a little....read through it but that's some pretty advanced stuff there.
__________________
Michael
Re-starting the neglected '77...http://67-72chevytrucks.com/vboard/s...=425464&page=9
THE "10" SILVERADO is offline   Reply With Quote
Old 08-13-2012, 11:45 PM   #4
VetteVet
Msgt USAF Ret

 
VetteVet's Avatar
 
Join Date: Jan 2005
Location: Kalamazoo, Michigan
Posts: 8,719
Re: Relay Question?

The purpose of a relay is to allow a higher voltage or load to be switched and controlled by a low voltage low draw circuit. This protects switching components such as the headlight switch, electric fans, electric fuel pumps switches, etc. The ignition switch is designed to carry the low amperage draw of the ignition coil so why do you want to put a relay there. If you want to keep the engine running if the switch cuts off you could just put a hidden toggle switch in the coil feed wire and feed it from any hot source off the fuse panel, doing away with the ignition switch altogether as the ignition source.

Having more than the normal voltage to the coil may be necessary if the engine is to be revved more than 6000 RPMs as in drag racing or if you are feeding more than the normal amount of circuits off the ignition switch.
__________________
VetteVet

metallic green 67 stepside
74 corvette convertible
1965 Harley sportster
1995 Harley wide glide

Growing old is hell, but it beats the alternative.
VetteVet is offline   Reply With Quote
Old 08-13-2012, 11:53 PM   #5
THE "10" SILVERADO
Registered User
 
THE "10" SILVERADO's Avatar
 
Join Date: Sep 2010
Location: Marble Falls, TX
Posts: 1,575
Re: Relay Question?

Quote:
Originally Posted by VetteVet View Post
The purpose of a relay is to allow a higher voltage or load to be switched and controlled by a low voltage low draw circuit. This protects switching components such as the headlight switch, electric fans, electric fuel pumps switches, etc. The ignition switch is designed to carry the low amperage draw of the ignition coil so why do you want to put a relay there. If you want to keep the engine running if the switch cuts off you could just put a hidden toggle switch in the coil feed wire and feed it from any hot source off the fuse panel, doing away with the ignition switch altogether as the ignition source.

Having more than the normal voltage to the coil may be necessary if the engine is to be revved more than 6000 RPMs as in drag racing or if you are feeding more than the normal amount of circuits off the ignition switch.
I want to cut the coil power feed with a toggle (for security when I'm away from the truck) but I want to put something like a latching relay in the feed to keep the power to the coil in case the toggle accidentally turns off driving.

So once the ignition and toggle are on it gets power but if the toggle goes off (once it has power) it will continue to have power until the ignition is cut.
__________________
Michael
Re-starting the neglected '77...http://67-72chevytrucks.com/vboard/s...=425464&page=9
THE "10" SILVERADO is offline   Reply With Quote
Old 08-14-2012, 12:50 AM   #6
fixit-p
Registered User
 
fixit-p's Avatar
 
Join Date: Dec 2008
Location: Yay Area CA
Posts: 2,329
Re: Relay Question?

If you want to latch the relay just jump terminal 87 to 86 that way the relay will energize itself regardless of the state of the kill switch and once the ignition is turned off the relay shuts down.
Attached Images
 
__________________
1965 GMC shortwide big window
1969 Chevy C20 long (for now)
2005 Silverado 2500HD Crew Cab


Quote:
Originally posted by:Abraham Lincoln "The trouble with quotes on the Internet is that it is nearly impossible to discern if they are genuine."
fixit-p is offline   Reply With Quote
Old 08-14-2012, 01:02 AM   #7
THE "10" SILVERADO
Registered User
 
THE "10" SILVERADO's Avatar
 
Join Date: Sep 2010
Location: Marble Falls, TX
Posts: 1,575
Re: Relay Question?

Quote:
Originally Posted by fixit-p View Post
If you want to latch the relay just jump terminal 87 to 86 that way the relay will energize itself regardless of the state of the kill switch and once the ignition is turned off the relay shuts down.
Thanks man! I figured I would end up with 2 relays and a complicated setup but that seems simple enough. Guess I'll only end up spending $5 for the relay then.
__________________
Michael
Re-starting the neglected '77...http://67-72chevytrucks.com/vboard/s...=425464&page=9
THE "10" SILVERADO is offline   Reply With Quote
Reply

Bookmarks

Tags
bosch, ignition, kill, relay, switch

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump


All times are GMT -4. The time now is 10:40 AM.


Powered by vBulletin® Version 3.8.11
Copyright ©2000 - 2024, vBulletin Solutions Inc.
Copyright 1997-2022 67-72chevytrucks.com