Hey guys I wired up a kill switch to a friends car. And a week later he blew a fuse.... it took me having to unhook the switch and run the fuel pump wire back together thinking maybe it was my wiring to find out it was only a fuse.
So we replaced the ffuse. A week later it blew again.
We put a fuse that was slightly higher amperage and its been fine since.
What is the correct way tto solving this? Rather then runnning the wrong sized fuse?
The switch is a rocker. And is rather small. (For stealth reasons).
Everything is crimped and heat shrinked... so its not some crappy electrical tape job.
Im currently out of town so im not sure what fuse it is or the exact size switch.

 

What kind of car is it?
What wire did you put the kill switch on?

 

Take the bigger fuse out and put the correct one back in. If the car is blowing the fuse with your kill switch installed, Something is grounding out. Could be a bad switch.

 

Thanks guys its a 95 civic 4 door. I hooked it up to the yellow and green wire that goes directly to the pump and thanks des. will do.
Could it be that the switch is to small?
I double checked all of my wiring... and them cut it and re did it again. And it blew one more time.
How do I know if the switch is no good? I have a ffew extras should I put a different one?
I bought the switch from orvac electronics. If that means anything. It was like a Buck...
I will pull it all apart when I get home and check everything again.
What can a bigger fuse lead to? I think we bumped it up like 5 amps. But he has a few spares so I will definitely have him change it.
I just called my friend and he said we changed it from a 20 to a 25 but he will change it back tomorrow.

 

Install the switch on the ground on the PGM-FI Main Relay instead of the power lead to the fuel pump. 94

 

I put my switch inline with the power supply wire to the fuel pump, been working great for the past 2 years, no blown fuses. Instead of hard wiring the switch there are quick disconnects on the original wire so i can just hook it back up to bypass the switch if anything goes wrong with it.

 

I have heard of doing the main relay. But when I took a look at it I wasnt sure which was the ground. Would it just be a black wire on the plug?
Do u cut and splice? Or tap into the plug? Its low voltage right?
If anyone has. A write up w. Pics that would help.
Also is the relay the same for an ek so I can do it to my car as well.

For the record I've had my kill switch on my 92 si for 5 years and never blew a fuse.
@MD426 did you add the quick disconnect? Cuz I don't think I've seen that before at least not on an eg. I've yet to check out my ek.
Thanks for all the responses guys its greatly appreciated.

EDIT: I think I see how your quick disconnect works now.
Couldn't a theive just fold back your seat and connect the two if he's even half smart?
I didn't splice right by the pump I went down the wire closer to the carpet for this reason.

 

What he said ^^^^^^^^^^^

If you put it on the coil of the relay you can almost run any size switch you want because your only pulling maybe 800mA to charge the relay.

Your other option is to install a relay on those wires near the pump use your switch to turn the relay on/off. Basically the same as above.

 

I suppose they could but the seat is bolted down and I have another switch for ignition hidden.

 

Personally id rather run it to the main relay I just have to figure out the correct way.
When u say to the coil,is that the same as the ground? Or a completely different wire?
Also is there only one ground down there? I have a multimeter so I guess all i have to is check which one has no ohms right?
If I was to add a relay to the inline what size or kind of relay would i need? Would it just be inline with the switch?
Excuse me if im not 100% electrically inclined my dad was an electrician for 30+ years so what i do know i learned from him. Its just hard to get him to help me w. Any of my cars.
Also im still in Utah working i will jump on this as soon as i get home.

 

Yes it is the black lead, it is the ground for the injector relays coil... http://www.the12volt.com/relays/relays.asp it is a low current ground, a 1A switch will work.

Wire it just like the power lead, cut the black lead and install the switch.

Cutting the ground to the PGM-FI Main Relay will "kill" the fuel injectors, the ECU/ECM, the fuel pump and a few engine solenoid/valves. 94

 

Awesome thanks alot guys I will get on this as soon as im home
Thank you thank you it is much appreciated I believe my switch is a 10A

 

That's not entirely correct. It will kill the fuel pump but does nothing to the ECU/ECM. I can't remember if its the souce for the injectors I would need to look at the schematic again but it might be.

The only connection to the ECU/ECM is for accident purposes. It basically prevents the car from staring if you were to get into an accident. So the signal comes from the ECU to the main relay not the otherway around. It serves no purpose at all as far as security goes.

 

Not so, there is a "signal" from the ECU/ECM to the fuel pump relays coil, [ground] there is a "signal". [12V+] from the PGM-FI Main Relay, [injector relay] to the ECU/ECM, [two (2) inputs, IGP1 and IGP2], engine will not run without power to the IGP inputs.

The PGM-FI Main Relay, [injector relay] supplies the power for the injectors, the ECU/ECM supplies the ground pulse, no IGP input = no ECU/ECM ground pulse to the injectors.

Just fixed a 97 Civic, [no start] IGP2 lead was broken, [some numb-nut had Ttaped into it for ign. power, the Ttap had sheared through all the wire strands].94

 

If you disconnect those wires sure the car wont run. It's because those wires provide a way for the ECM to shut the car down in the event of an accident. But the key here is that disabling the main relay the way you guys do does nothing to prevent ECU/ECM from making that connection. So you aren't actually disabling the ECU you are disabling the fuel pump and the injectors that is it.

I'll put it another way, you can completely remove the main realy put a jumper wire between the "hot" wire the fuel pump and the injector wire. The car will start. I put a you tube video up a while ago proving that. Can probably search you tube for main relay to find it. This is a decent kill but shouldn't be construed as more then it really is.

 

OK, maybe it's semantics, or maybe I'm not getting it...

If I put a switch on the ground for the PGM-FI Main Relay, that disables the fuel pump, [no power to it so it does not run] the fuel injectors, [no power to them so they can not pulse] the engine valves/solenoids, [no power to them so they can not work] and the ECU/ECM, [no power (12V+ signal) to it so it will not pulse the injectors].

Your saying that is not disabling the ECM/ECU, but you have to bypass the PGM-FI Main Relay to get the ECU/ECM working again????

Let me ask you this...

What are the odds, that once it gets around that you posted on youtube a "how to beat those pesky kill swithes Honda/Acura ownes put on their cars" that other HT members will start shitting on you, let me be the first...
Dumbass, no props at all. 94

 

No you don't need to bypass the main relay to get the ECM/ECU working that never stops working at least not with this kill anyway. The ECU send a negative pulse to the injectors. The main relay supplies the constant 12V signal to the fuel injector. A fuel injector is like a relay coil except then when a negative pulse is applied to it, it opens a valve. The main relay disables the fuel pump and the fuel injectors only.

I'm not to concerned with what other people "think".
There are other reasons to bypass a main relay. Like being stranded somewhere because the damn thing stops working. The main relay on Honda's is notorious for going out. Limiting information doesn't prevent theft. It only creates a bunch of misinformed people standing around wondering why their car got stolen because they depened on a so called "super kill".

Anyone that is interested in security would be a fool to think that disabling only the main relay is some magic bullet that is somehow superiour to any other form of kill. If your selling it as that then your only short changing the people that are depending on you to be an expert. A main relay kill should always be followed up by other well placed kills.

 

I have not and I do not think anyone else is saying that "killing the PGM-FI Main Relay is the end all for security, I definitely have never called it a "super kill" and I have always advocated as many layers of security as possible.

The point of a switch on the ground for the PGM-FI Main Relay is that it is far superior to a switch on the power lead to the fuel pump, for a number of reasons, for one your dealing with a low current ground instead of a high current positive.

You are wrong about disabling the ECU/ECM, it is disabled just as much as the fuel pump is disabled, the ECU/ECM will not work as it is supposed to, [supply a ground pulse to the injectors] if the 12V+ signal to IGP1&2 are not supplied, if the fuel injector relay is not working then there is no 12V + signal to the ECU/ECM, effectively disabling that part of the ECU/ECM, the only way to get the ECU/ECM to pulse the injectors is to supply that 12V+ signal to the ECU/ECMs IGP1&2 inputs, you are doing that when you jump power to the injectors and and fuel pump leads at the PGM-FI Main Relay, it is the injector relays output that supplies the 12V+ signal to the ECU/ECM.

Again, you are correct, a kill switch on the ground to the ECU/ECM is not the end all of security, it is however IMO better then a kill switch just on the power lead to the fuel pump for a number of reasons, number one is because it disables a number of things, not just the fuel pump. 94

 

 

This wasn't meant to be a peeing contest. But something is only disabled if it stops working.
The ECU in this case never stops working. It's always on its always doing its job. It has no idea you disabled the fuel injector.

The fuel injectors have been disabled because they no longer have current running to them. The ECU still continues to send the signal its responsible for to the fuel injector. If the ECU were disabled it wouldn't be as simple as running a hot wire to the injectors to get the car to start because the ECU would be non functional.

Analogy
If your car is running and you throw it in nuetral did you stop your motor from running? No because your motor has no idea nor does it care wether the car is in gear or not.

If you want to continue to say you have disabled the ECU that's up to you. I don't really care it's not my car you're working on anyway.

I would agree this is a slightly better kill then running a wire to the fuel pump and injectors but not because you are switching a low current signal. But because the Honda relay is far superior in terms of reliability then the aftermarket relays used on car alarms. JMO

 

"The fuel injectors have been disabled because they no longer have current running to them. The ECU still continues to send the signal its responsible for to the fuel injector"

See, that's my point, the ECU will not supply the ground pulse to the injectors if IGP1` or IGP2 at ECU/ECM does not have power, that power is supplied by the PGM-FI Main Relay, [injector relay], I have repaired a few Honda/Acura with that problem, [no power to IGP1 or IGP2 or both] there was nothing else wrong with these cars.

The first things we check on Honda/Acura that come to the shop with no injector pulse is, first is there power to the injectors if there is then it is an ECU/ECM problem so we check to see if there is power at the IGP1 and IGP2 terminals at the ECU/ECM, if not we supply power using a jumper, if engine runs we pull the harness to find where the break is, fix the break and power gets to IGP1&2 and the ECU/ECM then supplies the ground pulse to the injectors.

You can continue to say the ECU/ECM is not disabled, if it does not supply a pulse for the injector it is disabled JMO, nuff said.94

 

I don't know your test procedure nor your test equipment but you would need a voltage drop in order to see a "pulse".If you disconnected the fuel injectors you would need to provide some kind of load in parallel with your measurement device. Otherwise you will see nothing, that doesn't mean it doesn't exist. Similiar thing as if you took 3 resistors 100 ohm 10k ohm and 1meg ohm and connected one end to +12 and then used you multimeter to measure the voltage at the other end you would get +12V across all 3 resistors. No Load equals no voltage drop equals no waveform.

Even with the fuel injectors connected you would need a decent oscilliscope to see the waveform. The injectors are coils maybe a 100 milliohms each which means the voltage drop would be maybe a few millivolts. I went through all this when my main relay was having intermittent failures when the outside temperature got hot.

Anyway call it what you want your not advising me. I think the original poster got more information then he was asking for.

 

[QUOTE=fcm;44809296]I have not and I do not think anyone else is saying that "killing the PGM-FI Main Relay is the end all for security, I definitely have never called it a "super kill" and I have always advocated as many layers of security as possible.

The point of a switch on the ground for the PGM-FI Main Relay is that it is far superior to a switch on the power lead to the fuel pump, for a number of reasons, for one your dealing with a low current ground instead of a high current positive.

You are wrong about disabling the ECU/ECM, it is disabled just as much as the fuel pump is disabled, the ECU/ECM will not work as it is supposed to, [supply a ground pulse to the injectors] if the 12V+ signal to IGP1&2 are not supplied, if the fuel injector relay is not working then there is no 12V + signal to the ECU/ECM, effectively disabling that part of the ECU/ECM, the only way to get the ECU/ECM to pulse the injectors is to supply that 12V+ signal to the ECU/ECMs IGP1&2 inputs, you are doing that when you jump power to the injectors and and fuel pump leads at the PGM-FI Main Relay, it is the injector relays output that supplies the 12V+ signal to the ECU/ECM.

Again, you are correct, a kill switch on the ground to the ECU/ECM is not the end all of security, it is however IMO better then a kill switch just on the power lead to the fuel pump for a number of reasons, number one is because it disables a number of things, not just the fuel pump. 94[/Quote hes right i does disable the ecu