Parts Catalog Accessories Catalog Tech Info Tech Forums
 
  Search our site:    
 Cart  | Project List | Order Status | Help    
  Join us November 1st for Casino Night at the Pelican Parts Open House!
Benefiting LuMind - Research and Treatment for individuals with Down Syndrome
Go Back   Pelican Parts Technical BBS > 1- Porsche Technical Forums > Porsche 911 Technical Forum

Reply
 
LinkBack Thread Tools Rate Thread
Author
Thread Post New Thread    Reply
Registered User
 
Join Date: Jan 2003
Location: Los Angeles, CA
Posts: 1,801
Inexpensive very easy kill switch

I recently had surgery on my elbow and couldn't drive the Porsche for a while. I knew the battery was going to be dead when I finally got around to taking it out for a spin because I have a slow drain on the battery that I have been meaning to chase down for longer than I care to admit.
Being kind of a gadget freak I decided it would be easier to instal a kill switch than spend the time tracking down the leak.
I liked the idea of the extra security a kill switch would bring, and I could just use it to disconnect the battery when I was going to not be able to drive the car for a few weeks at a time.
Here's the car.


I have already moved a small battery to the smugglers box



I wanted something that could be reversible if I wanted to take it back out, didn't require any mods I couldn't reverse.
My plan was to remove the ash tray and install a kill switch there.
First I removed the ash tray and mount then I bought, from my local Pep Boys, 2 cables, a kill switch, some hardware from home depot and a grommet from the Mustang I am restoring.





I'm a big weight guy. My car weighs 2387lbs with a full tank of gas. I figured between losing the ash tray and mount I only gained a few ounces adding the switch and one extra cable. Next time I'll weigh it.
I only had to drill one hole to mount the switch in the ashtray area and it does not interfere if I want to remove it and put the ash tray back.
I ran the two cables thru an existing hole into the passenger compartment by the smugglers box right where I want to mount the switch













Total cost under $30. Total time less than an hour.

Steve
__________________
1983 SC sold, 1979 track/street car sold, 1962 356B T6 restorted and sold, 1982 SC never selling
1970 non sunroof roller sold
1967 Mustang resto project
stevevernondp.com

Last edited by Cdnone1; 01-29-2010 at 11:44 AM.. Reason: spelling
Old 01-29-2010, 11:35 AM
  Recommend this thread for the PelicanWiki    Reply With Quote #1 (permalink)
Registered User
 
Porsche Head's Avatar
 
Join Date: Mar 2002
Location: San Jose
Posts: 392
I have the same switch and am considering my options.

Did you run the NEG (ground) wires to the switch, If so all someone would have to do is cross the 2 terminals at the switch and it will start.

I was considering welding a box for the switch or mounting it higher with a plate to make it harder to access.
__________________
72 911E w/3.0, Dansk 2out, SSI's...RS look
88 M5 300hp
2004 GTI 1.8T
2011 VW Golf TDI
Old 01-29-2010, 02:25 PM
  Recommend this thread for the PelicanWiki    Reply With Quote #2 (permalink)
Registered User
 
Join Date: Jan 2003
Location: Los Angeles, CA
Posts: 1,801
I did use the ground, but you would have to cross the terminals plus have gotten around the ignition switch and steering lock.
It's not really for safety, that is just an added bonus.
I really did it because it eliminates the battery dying problem and looks cool.
My kid saw it this afternoon and thought it looks great.
Steve
__________________
1983 SC sold, 1979 track/street car sold, 1962 356B T6 restorted and sold, 1982 SC never selling
1970 non sunroof roller sold
1967 Mustang resto project
stevevernondp.com
Old 01-29-2010, 02:35 PM
  Recommend this thread for the PelicanWiki    Reply With Quote #3 (permalink)
Registered User
 
Join Date: Oct 2005
Location: Idaho
Posts: 1,721
Hi -

Looks nice and clean. Am I correct in assuming that with the way you wired the switch, it would not be good to turn it "off" if the engine was running? Only to be used after shutting the car off w/the ignition/key?

Tom
__________________
'74 911 Red Sunroof Coupe (not stock)
Old 01-29-2010, 02:50 PM
  Recommend this thread for the PelicanWiki    Reply With Quote #4 (permalink)
Registered User
 
Join Date: Jan 2003
Location: Los Angeles, CA
Posts: 1,801
Thanks and yes.
I shut the car off with it to see what would happen and all it did was kill the engine and all electronics.
You can't hit it with your hand when shifting and you would be hard pressed to accidentally turn it off as it is a push turn switch
Steve
__________________
1983 SC sold, 1979 track/street car sold, 1962 356B T6 restorted and sold, 1982 SC never selling
1970 non sunroof roller sold
1967 Mustang resto project
stevevernondp.com
Old 01-29-2010, 03:06 PM
  Recommend this thread for the PelicanWiki    Reply With Quote #5 (permalink)
Model Citizen
 
herr_oberst's Avatar
 
Join Date: May 2007
Location: Portland, OR
Posts: 6,223
Garage
Nice seats/steering wheel/deadpedal!
__________________
"Does anybody here remember Vera Lynn?"
Old 01-29-2010, 03:44 PM
  Recommend this thread for the PelicanWiki    Reply With Quote #6 (permalink)
Registered User
 
nineball's Avatar
 
Join Date: Jun 2009
Location: ohio
Posts: 4,128
doesn't it get annoying to have to setup your radio (presets, fader, eq, etc) and clock every time you hit the switch?
__________________
- He gave his father "the talk"
- Once while sailing around the world he found a shortcut
- He taught a german shepard how to bark in spanish
He is.... nineball. I don't always drive sports cars, but when I do I drive a 1983 911SC Targa. Stay fast my friends.
Old 01-29-2010, 04:18 PM
  Recommend this thread for the PelicanWiki    Reply With Quote #7 (permalink)
Registered User
 
Join Date: Jan 2003
Location: Los Angeles, CA
Posts: 1,801
Thanks on the seat etc.
Yes I have to reset the radio but I really only use it for traffic reports or the CD. It doesn't have any fader or other stuff and my car is so loud that you can't hear much anyways
I hardly ever look at the clock and it's easy to reset while I'm getting ready to go
Steve
__________________
1983 SC sold, 1979 track/street car sold, 1962 356B T6 restorted and sold, 1982 SC never selling
1970 non sunroof roller sold
1967 Mustang resto project
stevevernondp.com

Last edited by Cdnone1; 01-29-2010 at 04:25 PM.. Reason: spelling
Old 01-29-2010, 04:23 PM
  Recommend this thread for the PelicanWiki    Reply With Quote #8 (permalink)
Registered User
 
80-911SC's Avatar
 
Join Date: Feb 2009
Location: STOCKTON CA
Posts: 2,102
Garage
to stop the annoying resetting of the radio , just run another ground from the radio to the ground wire that runs from the battery to the switch .... that way the radio wont lose its stuff when the switch is thrown , the only time the radio would "die" is if the battery itself was disconnected ........
Old 01-29-2010, 07:45 PM
  Recommend this thread for the PelicanWiki    Reply With Quote #9 (permalink)
Registered User
 
Join Date: Jul 2000
Location: So. Calif.
Posts: 16,949
Quote:
Originally Posted by 80-911SC View Post
to stop the annoying resetting of the radio , just run another ground from the radio to the ground wire that runs from the battery to the switch .... that way the radio wont lose its stuff when the switch is thrown , the only time the radio would "die" is if the battery itself was disconnected ........
If the master switch breaks the battery ground circuit cable (which it does in this case), all circuits in the electrical system are inop even though a separate wire connects the radio to ground. Current needs a complete path from + to terminals of the battery.

To keep the presets active with this cutoff switch, connect a fused (e.g. 8A) wire between the large ground cables. Thus, even though the switch is OPEN, current can flow to ground from the radio. If there's an attempt to crank the engine, the 8A fuse will blow due to the high cranking current through the system. However, this circuit can allow the battery to discharge during storage as this wire still provides a ground path. To offset any long term discharge, connect a battery maintainer to the system to keep the battery fully charged despite the active radio preset circuit, alarm, etc.

Sherwood
Old 01-29-2010, 08:54 PM
  Recommend this thread for the PelicanWiki    Reply With Quote #10 (permalink)
Registered User
 
80-911SC's Avatar
 
Join Date: Feb 2009
Location: STOCKTON CA
Posts: 2,102
Garage
Quote:
Originally Posted by 911pcars View Post
If the master switch breaks the battery ground circuit cable (which it does in this case), all circuits in the electrical system are inop even though a separate wire connects the radio to ground. Current needs a complete path from + to terminals of the battery.

To keep the presets active with this cutoff switch, connect a fused (e.g. 8A) wire between the large ground cables. Thus, even though the switch is OPEN, current can flow to ground from the radio. If there's an attempt to crank the engine, the 8A fuse will blow due to the high cranking current through the system. However, this circuit can allow the battery to discharge during storage as this wire still provides a ground path. To offset any long term discharge, connect a battery maintainer to the system to keep the battery fully charged despite the active radio preset circuit, alarm, etc.

Sherwood
I am not an electrical engineer but
the "always hot is to the battery +
and his switch cuts the ground, effectively cutting the loop as you stated but if you go from the radio ground to the back side of the switch (the one from the battery to the switch) the battery would as I said be connected to the battery wouldn't it ???????which when the switch was thrown the radio would still be connected to a positive and a negative , unless i am missing something ........

Please by all means correct me if i am wrong but my cars I did this way and I dont reset my radio (and have done others the same way)

Last edited by 80-911SC; 01-29-2010 at 09:27 PM..
Old 01-29-2010, 09:19 PM
  Recommend this thread for the PelicanWiki    Reply With Quote #11 (permalink)
Registered User
 
NineOhOne's Avatar
 
Join Date: Apr 2009
Location: CA
Posts: 685
Quote:
Originally Posted by 80-911SC View Post
I am not an electrical engineer but
the "always hot is to the battery +
and his switch cuts the ground, effectively cutting the loop as you stated but if you go from the radio ground to the back side of the switch (the one from the battery to the switch) the battery would as I said be connected to the battery wouldn't it ???????which when the switch was thrown the radio would still be connected to a positive and a negative , unless i am missing something ........
You are correct.
Old 01-29-2010, 09:28 PM
  Recommend this thread for the PelicanWiki    Reply With Quote #12 (permalink)
 
Now Available for Ordering:   101 Projects For Your BMW 3 Series 1982-2000  [more info]
Registered User
 
80-911SC's Avatar
 
Join Date: Feb 2009
Location: STOCKTON CA
Posts: 2,102
Garage
the radio has a "always" hot , basically straight to the bat +
the ground goes to the bat -

his switch has two terminal one connected strat to the bat - "always" ground
the second when switched disconnects the battery ground from the chassis

assuming i am correct I'll continue

if you connect the radio ground to the " always"grounded side of the switch you have a continuous ground and a "always" hot positive basically your radio is hard wireded to the battery . Correct ?

so the presets will stay active ....

I did mine this way and its fine, I have done others and they work also .

Please feel free to explain the error of my ways if i missed it

I can draw it out in crayon and scan in a schematic of the set up if any one wants

Thanks for the back up Nine oh nine

Last edited by 80-911SC; 01-29-2010 at 09:39 PM..
Old 01-29-2010, 09:34 PM
  Recommend this thread for the PelicanWiki    Reply With Quote #13 (permalink)
Registered User
 
80-911SC's Avatar
 
Join Date: Feb 2009
Location: STOCKTON CA
Posts: 2,102
Garage
Sherwood ,

I haven't used your method but I am not going to call yo a dumba@@@@ for suggesting it but re read mine and you will see it will work, or read the last post that I spelled it out a little more in detail for you because you are obviously smarter than I am . If you cant get it with the second description I can get the crayons out or fire up auto cad and post it here if you need.

if you are worried about my way leaving the switch with an open ground path that is true it does but so does yours , mine just seems liked a dumbed down version of yours but it does work
Old 01-29-2010, 09:45 PM
  Recommend this thread for the PelicanWiki    Reply With Quote #14 (permalink)
Registered User
 
Join Date: Jul 2000
Location: So. Calif.
Posts: 16,949
Quote:
Originally Posted by 80-911SC View Post
I am not an electrical engineer but
the "always hot is to the battery +
and his switch cuts the ground, effectively cutting the loop as you stated but if you go from the radio ground to the back side of the switch (the one from the battery to the switch) the battery would as I said be connected to the battery wouldn't it ???????which when the switch was thrown the radio would still be connected to a positive and a negative , unless i am missing something ........

Please by all means correct me if i am wrong but my cars I did this way and I dont reset my radio (and have done others the same way)
You're correct. I misread your description.

Sherwood
Old 01-29-2010, 09:47 PM
  Recommend this thread for the PelicanWiki    Reply With Quote #15 (permalink)
Registered User
 
80-911SC's Avatar
 
Join Date: Feb 2009
Location: STOCKTON CA
Posts: 2,102
Garage
Quote:
Originally Posted by 911pcars View Post
You're correct. I misread your description.

Sherwood
Thank you..........
Old 01-29-2010, 09:53 PM
  Recommend this thread for the PelicanWiki    Reply With Quote #16 (permalink)
Registered User
 
0396's Avatar
 
Join Date: Sep 2005
Posts: 449
Quote:
Originally Posted by Cdnone1 View Post
Thanks and yes.
I shut the car off with it to see what would happen and all it did was kill the engine and all electronics.
You can't hit it with your hand when shifting and you would be hard pressed to accidentally turn it off as it is a push turn switch
Steve
I’m no electrical engineer, but I was advised years ago that: if one disconnects the battery while the motor is running.. the alternator will keep it running… and this could blow the diodes in the alternator.

That's the reason why , many higher end 'kill ' switches have a relay that is also connected to the 'exciter' wire to the alternator ... which 'grounds' it

Last edited by 0396; 01-30-2010 at 05:43 AM..
Old 01-30-2010, 05:40 AM
  Recommend this thread for the PelicanWiki    Reply With Quote #17 (permalink)
Registered User
 
Join Date: Jan 2003
Location: Los Angeles, CA
Posts: 1,801
I think if the battery dies the alternator will continue to try and run the car, but if you interrupt the the electrical loop by disconnecting the ground nothing will work.
Steve
__________________
1983 SC sold, 1979 track/street car sold, 1962 356B T6 restorted and sold, 1982 SC never selling
1970 non sunroof roller sold
1967 Mustang resto project
stevevernondp.com
Old 01-30-2010, 03:13 PM
  Recommend this thread for the PelicanWiki    Reply With Quote #18 (permalink)
Registered User
 
80-911SC's Avatar
 
Join Date: Feb 2009
Location: STOCKTON CA
Posts: 2,102
Garage
Quote:
Originally Posted by Cdnone1 View Post
I think if the battery dies the alternator will continue to try and run the car, but if you interrupt the the electrical loop by disconnecting the ground nothing will work.
Steve
i don't think so , i could be wrong but I don't so.
dis connect battery and motor should stay running, if not see alternator trouble shooting guide
But if you are having trouble with a dying battery which would explain the need want or urging to install the dis connect you may have just answered the ? of what is causing it . answer ? alternator .
Old 01-30-2010, 06:07 PM
  Recommend this thread for the PelicanWiki    Reply With Quote #19 (permalink)
Registered User
 
Join Date: Jan 2003
Location: Los Angeles, CA
Posts: 1,801
When I turned the disconnect switch off everything died.
I think there is a difference between a dead battery and an open loop electrical system.
But I'm no expert you could be right
Steve
__________________
1983 SC sold, 1979 track/street car sold, 1962 356B T6 restorted and sold, 1982 SC never selling
1970 non sunroof roller sold
1967 Mustang resto project
stevevernondp.com
Old 01-30-2010, 07:30 PM
  Recommend this thread for the PelicanWiki    Reply With Quote #20 (permalink)
Old 01-30-2010, 07:30 PM
Reply

Thread Tools
Rate This Thread
Rate This Thread:

 



All times are GMT -8. The time now is 11:59 PM.


 
Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2014, vBulletin Solutions, Inc.
Search Engine Optimization by vBSEO 3.6.0
Copyright 2011 Pelican Parts - Posts may be archived for display on the Pelican Parts Website -    DMCA Registered Agent Contact Page
 

DTO Garage Plus vBulletin Plugins by Drive Thru Online, Inc.