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I recently bought a 1990 Toyota pickup 3.0 and I know how sought after these cars are both legally and illegally. For my own piece of mind I've decided to install a kill switch in my vehicle. After watching Chris Fixes tutorial on kill switches and finding out that the COR works as the fuel pump relay I was planning on installing a kill switch into the COR. Before I do this though I was wondering if this is possible and if so, is there anything I should be aware of before installing the switch.
You're not going to install anything "into" the Circuit Opening Relay. I assume you plan to put a switch in the FC line to the relay. That way, your truck will start, run a few seconds, then quit. Probably one of the better kill switch plans (once the truck starts, people will notice the perp, so he won't have time to search out the hidden switch. Maybe.)
Under the passenger seat there is a connector that has the actual fuel pump power wire on it. This is after the COR in the circuit. I left it unplugged one time by an accident and the truck just cranks and cranks with no start.
You could probably solder a switch inline and mount it under the shifter boot, or under the passenger seat. Just have to remember to not yank the seat out with it attatched!
I think it’s the blue wire for an 89’ pickup. Cross reference your FSM to be sure.
Putting the switch in line from the VAF to the COR at the ECU seems to me the best (& easiest) way to go (as Scope mentions truck will run for a second & then die):
Under the passenger seat there is a connector that has the actual fuel pump power wire on it. This is after the COR in the circuit. I left it unplugged one time by an accident and the truck just cranks and cranks with no start.
You could probably solder a switch inline and mount it under the shifter boot, or under the passenger seat. Just have to remember to not yank the seat out with it attatched!
I think it’s the blue wire for an 89’ pickup. Cross reference your FSM to be sure.
I think I'll give that a try, seems a lot easier to install and replace if somethjing goes wrong, thanks.
good idea for theft security. One thing worth noting, from what Ive read about toyota thefts of this generation, is that a fairly common tactic is to put the truck in neutral and roll it out of driveways and then onto a trailer. Just food for thought. I dont like the idea of anyones truck winding up south of the border with a bunch of ugly stickers on it.
I use a remote control relay from Gamma Electronics to cut the 12v to the igniter in my 85. In fact I used several relays and an alarm, so when the relay is set trying to start the truck sends juice to the alarm instead of the igniter (opening the doors, sliding window, or the gas tank door also triggers the alarm). The security stuff is mostly under the hood, which locks, making it pretty tricky to defeat. Then for the tow truck threat I got a GPS tracker (tkstar from Amazon with Speedtalk sim), also locked under the hood. Just not gonna be that easy to steal my rig if everything is set right, even if you know my system. The problem it created is all the relays run down the battery, so I cut power to the system when parked for a long time. When power is cut, there's no voltage at the igniter.
How about another approach? Just put a switch in-line with the fuel-pump near the top of the tank. It's just three screws to pull off the plate to access the tank top. You could place the switch near where the backseat hinges are, and it's a simple reach from the driver's seat to flip/push/pull the switch.
How about another approach? Just put a switch in-line with the fuel-pump near the top of the tank. It's just three screws to pull off the plate to access the tank top. You could place the switch near where the backseat hinges are, and it's a simple reach from the driver's seat to flip/push/pull the switch.
I thought about doing this but I really don't want to have to drop the tank or lift the bed right now, I figured when I have to do either of those for another reason I'll just add a second kill switch while I'm there.
I use a remote control relay from Gamma Electronics to cut the 12v to the igniter in my 85. In fact I used several relays and an alarm, so when the relay is set trying to start the truck sends juice to the alarm instead of the igniter (opening the doors, sliding window, or the gas tank door also triggers the alarm). The security stuff is mostly under the hood, which locks, making it pretty tricky to defeat. Then for the tow truck threat I got a GPS tracker (tkstar from Amazon with Speedtalk sim), also locked under the hood. Just not gonna be that easy to steal my rig if everything is set right, even if you know my system. The problem it created is all the relays run down the battery, so I cut power to the system when parked for a long time. When power is cut, there's no voltage at the igniter.
While that sounds like a much securer option, and props to you for being able to set that all up, my knowledge of electronics is very limited so thats why I'm think about starting with a COR kill switch and then go from there. I am curious about that GPS tracker as that was probably my next upgrade besides a removable steering wheel, do you you like the model you use and is it justifiable for the cost?
I thought about doing this but I really don't want to have to drop the tank or lift the bed right now, I figured when I have to do either of those for another reason I'll just add a second kill switch while I'm there.
Ah. In a 4Runner it's super easy to get to the tank top, but it sounds like in the pickup...not so much.
You're not going to install anything "into" the Circuit Opening Relay. I assume you plan to put a switch in the FC line to the relay. That way, your truck will start, run a few seconds, then quit. Probably one of the better kill switch plans (once the truck starts, people will notice the perp, so he won't have time to search out the hidden switch. Maybe.)
Putting the switch in line from the VAF to the COR at the ECU seems to me the best (& easiest) way to go (as Scope mentions truck will run for a second & then die):
While that sounds like a much securer option, and props to you for being able to set that all up, my knowledge of electronics is very limited so thats why I'm think about starting with a COR kill switch and then go from there. I am curious about that GPS tracker as that was probably my next upgrade besides a removable steering wheel, do you you like the model you use and is it justifiable for the cost?
This is the tracker / sim combo I'm currently using: https://smile.amazon.com/gp/product/B072SM52XY/ https://smile.amazon.com/gp/product/B073ZMVZ3K/
I went through a few different similar trackers before getting this one; it has a bigger battery than most. I put a USB outlet under the hood for it so it never goes dead now. I think the current setup is worth the peace of mind for $60/year to keep the sim running. Prior to getting this one with the large battery and adding an outlet under the hood so it is plugged in all the time, it took too much effort to keep the tracker charged up all the time; about 75% of the time the battery would be dead or the sim expired (after a year). Depending on your phone plan, you might be able to get a cheaper sim card for the tracker.
So I know this thread is old, but it's also the most current one. I've seen a couple posts related to this as well. If I add a switch inline to the FC wire, the truck will start and then die a few seconds later? I am curious because on another thread@wyoming9 says he would break the circuit at the fuel pump ground.
For what it is worth you now eliminate just jumping B+ to Fp which any thief having done their research would do it would bypass 95% of all fuel system kill switches
I guess what I am wondering... are you saying that if you break it at the FC line, you can still jump B+ and FP to start the car and that's why you break it at the FP ground instead? Or are you saying if you break it at the FC line you prevent them from being able to jumper the connections to start the car?
it looks to me like Fp would be the full current ground line to the fuel pump? while Fc is lower current, controlling the relay, so maybe a better option? another way to look at it: here is a diagram for the 22re, Fc also includes the fuel pump bypass test connection that eliminates the air flow metering flap from the circuit: https://www.4crawler.com/4x4/CheapTr...shtml#FuelPump
if you open that Fc connection with a kill switch, i don't see how the fuel pump could run so it's not going to power the truck for very long... maybe residual fuel pressure in the lines?
it does look like jumpering B+ and Fp could start the vehicle, because it bypasses the COR completely, but where and how would you do that? it would take an intimate knowledge of old toyota truck wiring, which i suspect that few in this day and age will have.
if you are worried that messing with it could cause reliability problems(?), maybe install the kill switch with pluggable jumper connections and drive it around for awhile; if it dies you can unplug the switch, return to factory wiring.
1) If you interrupt FC, as long as the ignition switch is in "crank" position, the fuel pump would run and engine would fire up. As soon as you release IGN switch it would shut off.
Like Scope said, the thief would either think there is something wrong with the truck OR There is a kill switch somewhere. Seems more for the thief to wonder about
Advantage of this is you'll need thinner wire and lower current rating, hence smaller switch.
2) If you interrupt FP ground, the engine will not fire up at all. However, you would need thicker wire to carry the current FP needs to run.
Originally Posted by osv
if you are worried that messing with it could cause reliability problems(?), maybe install the kill switch with pluggable jumper connections and drive it around for awhile; if it dies you can unplug the switch, return to factory wiring.
^^^ Good Idea which I used on one of my kill switches.
Last edited by RAD4Runner; 03-15-2024 at 09:29 PM.
Based on the diagram, you could interrupt the direct fuel pump ground, the fuel pump switch ground, or the starter relay ground- all of which would give you slightly different results. I would probably interrupt the fuel pump switch ground based on the discussion above.
1) If you interrupt FC, as long as the ignition switch is in "crank" position, the fuel pump would run and engine would fire up. As soon as you release IGN switch it would shut off.
i see, L1 and L2(via STA?) duplicate the same function to some degree, albeit very briefly with the L2 circuit and crank-only action? forgot about that.
many years ago i bought a 2-door '66 chevy impala, the p.o. put a kill switch on it, and i somehow turned the switch on accidently(?), engine wouldn't turn over... swapped out the starter, etc., trying to get the car running, then somebody who knew the car reminded me about the kill switch, duh
1) If you interrupt FC, as long as the ignition switch is in "crank" position, the fuel pump would run and engine would fire up. As soon as you release IGN switch it would shut off.
Like Scope said, the thief would either think there is something wrong with the truck OR There is a kill switch somewhere. Seems more for the thief to wonder about
Advantage of this is you'll need thinner wire and lower current rating, hence smaller switch.
2) If you interrupt FP ground, the engine will not fire up at all. However, you would need thicker wire to carry the current FP needs to run.
^^^ Good Idea which I used on one of my kill switches.
The FC wire does seem like the way to go. I believe I can wire a switch inline to that and hide it pretty easily. Any time I mess with wiring I like to make jumpers using de-pinned factory connectors to make it reliable and also easy to switch back to stock if needed!
Blue 1986 Toyota 4Runner stolen at around 3am 03/08/24 in the Golden Hill/South Park area. If seen please contact San Diego Police Department with CASE#24301185 LICENSE PLATE #: 6FNU235
guess it's time to be thinking about a kill switch!
05-16-2021, 02:27 PM
