Killswitch that prevents power to starter motor

Charging, starting, lighting, gauges, HVAC

Moderators: FORDification, Thunderfoot

Post Reply
bph
New Member
New Member
Posts: 37
Joined: Sat Apr 19, 2014 9:16 pm
Location: Wimberley TX

Killswitch that prevents power to starter motor

Post by bph »

Hi all,

I looking for some guidance on installing a kill switch for my 1970 F250 360 Camper Special. It was stolen last week and I was able to recover it from a homeless camp. I'm hoping to install a kill switch, hood lock and maybe (funds permitting) some kind of visual deterrent like a wheel lock or disc lock.

To install a kill switch between the ignition switch and the solenoid, would the proper ignition switch wire be the "Coil Start and Prove Out" position?

I believe that the following picture depicts the ignition switch pin layout for my 1970:
Image

Based on my amateur inspection of the Master Wiring Diagram, I came to the conclusion that the circled pin on the far right leads to the "S" side of the solenoid/starter motor relay.

Would this be the correct path for inserting a kill switch if I wanted to keep the starter from being operated when the kill switch is engaged?

Thank you!
zgerbic
New Member
New Member
Posts: 78
Joined: Sat Jun 27, 2020 12:37 am

Re: Killswitch that prevents power to starter motor

Post by zgerbic »

bph,
Looks like the right connection based on the wiring diagram.

The wire going from the ignition switch to the solenoid would be a good place to put a kill switch however if you have a truck with an automatic trans, you could put the kill switch after the neutral safety switch. This may be located on the steering column. Alternately you could put in a DPDT or DPST heavy duty switch with one side killing the power to the ignition and the other side killing the power to the solenoid.

If you don't get the hood locked, the easiest place to add ignition power and jump the starter to steal the truck is at the solenoid. You might also need to put a plate with several safety screws over the solenoid switch/wiring itself cutting off access to the connections.

I believe most people these days don't know what is a manual choke is so I always park my truck with the choke pulled all the way on. I would expect better than even odds that someone will just flood out the engine trying to start it, if they can get it to crank.

Regards
Tony
User avatar
basketcase0302
100% FORDified!
100% FORDified!
Posts: 6805
Joined: Thu Jan 26, 2006 7:11 am
Location: Hawthorne, Florida

Re: Killswitch that prevents power to starter motor

Post by basketcase0302 »

I highly suggest not tapping into any wire right at the ignition switch as most thieves will simply drop the switch down and then be able to see what you've done.
I out the Viper brand car alarm into both BC#16 and my 71' Ranchero, (loved it due to the remote control features they have). But the best feature it had was an ignition disable circuit, (yes that part of it requires you cut into the coil wire UNDER THE HOOD where a thief won't be able to see once you get the hood locked down). Here's one of the Viper alarms, (well worth every single penny spent on it) but maybe take a look at other brands too that have an ignition disable circuit.
https://www.ebay.com/itm/224449957786?e ... OSwRd1gcgm~

And this was my EASY way to lock down the hood, (sorry I can't remember the exact length of cable). I use these all around my property also as the feature of setting your own combination makes them a nice cable lock. I highly recommend making sure you have no less than 2 small portable fire extinguishers in the truck before you decide to lock the hood, (from someone who's had engine fires before) as if you need to get under the hood quickly now you've added an obstacle. :wink:

https://www.ebay.com/itm/304053402215?e ... SwHC9g32GG

I'd count my blessings to have gotten the truck back! Down here in Florida our bumps wind up in shipping containers a few hours after stolen headed for South America or overseas when stolen. :pray:
Jeff
http://www.fordification.com/forum/view ... 22&t=46251
SOLD-71 F-350 dually flatbed, 302 / .030 over V-8 with a "baby"C-6, B & M truckshifter, Dana70/4.11 ratio, intermittent wipers, tilt steering, full LED lighting on the flat bed, and no stereo yet (this way I can hear the rattles to diagnose)! SOLD!
Many Ford bumps / one 76' EB / and several dents through the years.
A lot of "oddball" Ford parts collected from working on them for 34 years now!
2008 Ford Escape 4 x 4
DisneysPatB
Preferred User
Preferred User
Posts: 279
Joined: Wed Feb 08, 2017 7:58 pm
Location: Sunland, CA

Re: Killswitch that prevents power to starter motor

Post by DisneysPatB »

Hey Jeff, can you post a picture of how you have your lock and cable set up?

Thanks
Pat
1970 F250 460 C6 - Project - Currently not running.
1999 Dodge Durango SLT 4 x 4 5.9 Magnum -not running.
1999 Toyota Corolla - Daily Driver.

https://fordification.com/forum/app.php ... y/album/43
bph
New Member
New Member
Posts: 37
Joined: Sat Apr 19, 2014 9:16 pm
Location: Wimberley TX

Re: Killswitch that prevents power to starter motor

Post by bph »

basketcase0302 wrote:I highly suggest not tapping into any wire right at the ignition switch as most thieves will simply drop the switch down and then be able to see what you've done.
:
Yes, I would follow that wire from the ignition and then tap into it at some distance beyond the switch. I'll check out those Viper alarms, thanks!
bph
New Member
New Member
Posts: 37
Joined: Sat Apr 19, 2014 9:16 pm
Location: Wimberley TX

Re: Killswitch that prevents power to starter motor

Post by bph »

zgerbic wrote:bph,
Alternately you could put in a DPDT or DPST heavy duty switch with one side killing the power to the ignition and the other side killing the power to the solenoid.
Interesting. So, with my original plan, having a switch between the ignition switch's "Coil Start & Prove Out" pin and the Solenoid's "S" terminal...would that be "killing the power to the solenoid" or "killing the power to the ignition", as you stated?

Regarding kill switch configurations (poles and throws), I've also read a neat idea of using a SPDT throw where the "kill" throw of the switch is wired directly to the + terminal of the car horn, so when in kill switch mode the horn would blow any time the ignition is engaged into the "Coil Start" position..
User avatar
j41385
Preferred User
Preferred User
Posts: 288
Joined: Sun Jan 23, 2005 7:07 am
Location: Albany, Oregon Territory

Re: Killswitch that prevents power to starter motor

Post by j41385 »

You could always just remove the coil wire that goes from the coil to the distributor.
1968 F100 Took the running 390 out, and installed a Built 300 with AOD.
Engine Video... http://youtube.com/watch?v=2xgYd2u79NU


Image

Image Image
Ohiotinkerer
Blue Oval Fanatic
Blue Oval Fanatic
Posts: 852
Joined: Wed Nov 09, 2016 5:49 pm
Location: Galion, Ohio

Re: Killswitch that prevents power to starter motor

Post by Ohiotinkerer »

Another way to disable it is pull the rotor out of the distributor.....I do that when I travel with my bump.....something else to consider is a shut off switch on the fuel line......they will get it started but won't be going very far - mine on a cold start will run about 2 minutes before it runs the carb and line dry........
"Life is a garden - dig it"........... :thup:

1968 F100 2wd - Rangoon Red - 360 w/T18 - power steering and brakes
1997 Honda CBR 900RR
User avatar
basketcase0302
100% FORDified!
100% FORDified!
Posts: 6805
Joined: Thu Jan 26, 2006 7:11 am
Location: Hawthorne, Florida

Re: Killswitch that prevents power to starter motor

Post by basketcase0302 »

="DisneysPatB"Hey Jeff, can you post a picture of how you have your lock and cable set up?
Thanks
Pat
Pat,
I'm sorry but I sold BC #16 that I had the cable lock on.
If memory serves me right I just ran the small end of the cable lock up around the hood section, (as I was closing the hood) then ran it down around the center radiator core support leaving the combination part accessible through the front grill. Thinking about what i just wrote it might not work on 67'-69', (due to the grill) as i reached through the grill opening to twist the combination to lock and unlock? :hmm:
It's not the best preventative but will for sure slow them down as to cut that cable lock off would require some precision and a lot of noise. :thup:
Jeff
Jeff
http://www.fordification.com/forum/view ... 22&t=46251
SOLD-71 F-350 dually flatbed, 302 / .030 over V-8 with a "baby"C-6, B & M truckshifter, Dana70/4.11 ratio, intermittent wipers, tilt steering, full LED lighting on the flat bed, and no stereo yet (this way I can hear the rattles to diagnose)! SOLD!
Many Ford bumps / one 76' EB / and several dents through the years.
A lot of "oddball" Ford parts collected from working on them for 34 years now!
2008 Ford Escape 4 x 4
User avatar
chazskinz
New Member
New Member
Posts: 49
Joined: Fri Jan 09, 2015 2:23 pm
Location: MD

Re: Killswitch that prevents power to starter motor

Post by chazskinz »

Awesome suggestion for the choke pull out!
:yt:
zgerbic
New Member
New Member
Posts: 78
Joined: Sat Jun 27, 2020 12:37 am

Re: Killswitch that prevents power to starter motor

Post by zgerbic »

bph,
What I meant about using the double pole switch is that one set of contacts opens the power to the ignition coil and the other set of contacts prevents power from being sent to the starter solenoid. The biggest problem is figuring out where to put the switch under the dash away from the ignition switch itself. Having the horn blow is also an interesting modification.

Removing easy access to the starter solenoid contacts would really help. Just about anyone who is familiar with older Fords already knows you can just pull the two wires, jump the coil wire to hot with an alligator clip and short the starter contact to start the truck. Two people could take a truck in 20 to 30 seconds.

Others have mentioned taking out the rotor or pulling out the coil wire. While these will work, I find that having to open the hood to pull something is really inconvenient for the truck owner and over time just not done all the time. Watching the owner opening the hood while in a parking lot or at home, someone would realize exactly where to go to put the truck back in running order for a fast get away.

Just to throw this in, I used to have a 67 VW (mustang killer) that I worried a lot about getting stolen. Since it had a line lock on the front disk brakes, I put a switch between the ignition wire and the line lock solenoid and would park the car with the switch on. If someone started the car and took off, the first time they stepped on the brakes the front wheels would permanently lock. Hard to drive a car with the wheels locked and easily noticed.

I am sure there are other creative ways to lock down older vehicles, and it would be good to get any other ideas to protect our precious trucks.

Regards
zgerbic
New Member
New Member
Posts: 78
Joined: Sat Jun 27, 2020 12:37 am

Re: Killswitch that prevents power to starter motor

Post by zgerbic »

One other thing I forgot to mention is to use the tach connection (or add one to the coil for protection). If the truck still has points, putting in a switch to ground on the tach wire will prevent any spark. If there is a concern about shorting an electronic ignition, a small value (maybe 2 ohms), couple watt resistor could be used in the connection to ground. Spark will be extremely weak or non-existent but not risk burning out the electronic ignition.

Regards
Post Reply