Is it fine to have a kill switch on the EFI fuse since it is always getting power? I've already kind of done this using 14 gauge wire and a switch out of a 4runner.

​

 

I would be very careful with that. The wire TO the EFI fuse is either protected by the 30amp AM2 fuse http://web.archive.org/web/201204170.../2powersou.pdf , or, according to my '94 EWD, only the fusible link. So if you have a short to ground anywhere along that stretch of wire to your cab (and before your inline fuse), the wire has to carry 30 amps (or fusible link amperage, if my EWD is correct) before the AM2 fuse blows. In run-of-the-mill house wiring, 14ga wire is okay for 15amps. (This is apples and oranges, but you get the idea.)

Replacing the EFI fuse with a switch is clever; it's easy to do and easy to reverse. But you could significantly reduce your risk by splicing a switch into B-Y wire from the IGN fuse to the EFI coil. That wire is already under the dash, so your wire run to the switch is much shorter (and as a result, much more discrete). If you're worried about being able to easily reverse it (say, you want to sell the truck and somehow a kill switch is not a positive), you could use opposite gender "bullet" connectors at the splice. To disable the switch, just unplug the connectors from the switch and plug them into each other.

If you want to get really fancy, you can put the switch in the FC circuit from the VAF to the COR (again, under the dash, but over on the passenger side). It is sometimes said that a clever thief will immediately suspect a "kill switch" when the truck cranks but won't fire. With the switch in the FC circuit, the truck will start right up but only run for a few seconds. A thief who really knows his Toyotas might then suspect such a kill circuit, but by then he's already attracted attention to the truck that keeps starting and stopping.

 

I actually like that idea of a switch from the VAF to COR a lot. I'll probably splice a switch there.

 

Second Scope's comments.
It's also often safer, and requires thinner wires to put kill switches on low-current circuit like relay coil, instead of load, side.
AND I SUGGEST YOU TAKE DOWN PICTURE OF YOUR KILL SWITCH AND WHERE YOU PUT IT.
Thieves also do their research on forums

 

Uh, not really.

It's a popular movie trope. Lots of young men in black turtle-necks, sitting in a darkened room with giant computer screens. After a few seconds, one shouts "I'm in!"

If you're a crack-head looking to quickly steal some transportation out of here, it's much easier to just walk down any street with a pair pliers and a rock. Trying to figure out where STERFRY333 even lives is a lot more work.

 

Haha true

 

I ran my switch direct to the EFI fuse, it also resets the ECU whenever I trip it. Nice to clear a check engine light quickly but sometimes its gotta warm up for a bit after I trip it.

 

Put the switch on the fuel pump wire and then it wont mess with the ECU at all. It's what I did on my 3rd gen 4runner. Switch is hidden in a place that can be reached from the drivers seat

 

I like that idea. Must be pretty easy to do, just splice a wire?

 

Ya' gotta make up yer mind.

In the the FC circuit, the truck will start, run for a few seconds, then quit. In the fuel pump circuit, it will crank but will not fire. Plus you're switching a much higher current; if your switch gets damaged by the current (not likely, but something to think about) you won't be able to start it.

 

I really don't know what wire on the ECU to splice to do the first option. I'm still in the planning phase of doing this so nothing has really been decided yet. If I can figure out the first option I'll most likely do that as it's harder to tell it's a kill switch.

 

The FC wire to the COR should be G-Y to pin 4, if that means anything to you. The VAF grounds it to close the COR.

At the COR, the Fuel pump wire is L (bLue) to pin 1. The COR connects the wire to battery to run the pump.

Got a multimeter? Don't try to do anything electrical without one.

 

Im under the glovebox right now, I do see a GY wire going to a 6 pin relay above the ECU. Is that the one I'm looking for? Or is it a wire going to the ECU? here's a picture.

I think that's the one. The label on the plug says it's connected to pin 4. My Haynes Manuel says it's just G but so far it's gotten most of the wire colours wrong.

 

What does your multimeter tell you?

if I'm correct, with KOEO, you should get battery (~12v) on the G-Y wire. When your assistant pushes the vane in the VAF, G-Y should go to ground, the relay should close, and the fuel pump start. Then you know you have the correct wire.

No assistant? Well, you could just use a wire to connect G-Y to ground. If it's the correct wire, the pump will start. But what if it isn't? What if it is connected directly to battery (not through the relay coil)? Then shorting it to ground will blow a fuse. (If you short W-R to ground, you'll blow the EFI fuse.) So you could use a test-light to ground. (Why would that make a difference? Why would it work?)

 

Yeah I got my friend to push the vane open and it got power. I'm genuinely surprised how easy this was, like you take the glovebox off and it's literally right there. I though I'd have to sort through tons of wire and it would be buried behind stuff,but nope, super easy to get to. If you hide it right no one will know there's a switch and just assume you drive a POS. I'll probably add on my parent post and explain how to do this or make a 'write up' (not sure how much you guys like stuff being posted) as this is really simple.

 

Mr. Scope:
I recently installed this kill switch (interrupting the G-Y wire). It totally worked but when I went for a test drive, a few miles down the road, I was gearing down from 5th to 4th and the truck lost power and stalled. I saw that the EFI fuse blew, replaced it and was back on the road but stalled again on the way home (gearing down again, this time from 4th to 3rd). So I replaced the EFI fuse again but this time, upon starting, the fuse blew again and I was stuck on the road. Luckily a Jeep guy saved me and towed me the rest of the way home; pls don't tell the moderators as I will probably be kicked off Yotatech in shame).

I've searched the forums and learned about the O2 wires getting burnt and shorting and did the test outlined by RAD4Runner here. No luck, so my theory is it had to be my shoddy kill switch install + the sudden jerk of downshifting?. My question is if a piece of exposed G-Y wire touch the W-R, would that be blowing the fuse? I've since re-wired the kill switch and so far I haven't been able to blow the fuse.

 

Probably haha. Yeah make sure there are no exposed wires. I've been driving with the kill switch in for months now and have never had an issue (apart from one time I mistook to the switch for the light bar switch and stalled haha)