dgerej2

This is a kill switch wiring schematic. The author insists that a relay be used when doing a kill switch install.


The schematic is not easy to understand IMO. I don't understand the purpose of the numbers. Anyway, I have come to the conclusion that I will need some sort of 4 channel relay for the job. Excuse me if my terminology is incorrect. According to my research, I will need a SPDT relay. Radio shack has 4 different SPDT relays:

10 amp 12 volt
1 amp 12 volt
2 amp 7-9 volt
1 amp 5 volt

Will any of these work? Do I need something else? Thanks

The schematic was taken from the link below:
http://www.jdmuniverse.com/forums/ho...-switch-2.html

deschlong

iTrader: (8)

10 amp 12 volt probly

Numbers are just numbers used to designate the terminal ... standard terms, not sure what significance they have, if any.

Raid a junkyard and get one there for a dollar - honestly there are thousands of them. Horn relay for a Honda will do (RC-2022 or something, it's mounted on the fuse box usually)

wrx-killer-Sti-eater

iTrader: (1)

The main relay is a better fourm of kill switch and relocate it. If I was a theif and did not here the pump. I would rip up the back seat and tag 12 volts stright to the pump. This will easily bypass this kill switch.

fcm

Ditto the above^^^, "kill" the PGM-FI Main Relay itself or just the fuel pump relay, even better "kill" both, relays are not needed, power, [12V+] is not needed and very small, [easy to hide] 1A on/off switches can be used.

Installing a "kill" switch on the ground for the PGM-FI Main Relay, [fuel injector relay] will disable the fuel injectors, the fuel pump, the ECU/ECM and a few engine valve/solenoids.

Installing a "kill" switch on the ECU/ECM control lead to the PGM-FI Main Relay, [fuel pump relay will disable the fuel pump, without the need for the relay or wiring.

Do the main ground for the PGM-FI Main Relay and do the ECU/ECM control lead for fuel pump relay as a back-up.94

PS This will help you understand relays... http://www.the12volt.com/relays/relays.asp there is lots of usfull info here... http://www.the12volt.com/

dgerej2

Thanks guys. I'm surprised the DIY I was going to do is not all that great. Both of your posts make feel glad I didn't start anything yet.

I did some homework on main relays. It looks like the locations of them differ quite a bit.

Here is a pic of one inside a '94 ex:



This is the closest thing I can find for a reference starting point. I have a '99 Civic Ex.

Would I just need to find the solid black wire running to the relay? Wouldn't that be my ground? If so, all I would need to do is hook up a 1A On/Off switch to the ground wire running to the relay?

Why should I relocate the relay? How easy would over riding a main relay kill switch be if I didn't relocate the main relay?

fcm

92-03 Civics have PGM-FI Main Relay in the same place.

Relocating the PGM-FI Main Relay will make it harder for a thief to bypass the kill(s).

I did not relocate mine, I just did not install the switch, [cut PGM-FI Main Relay leads] at the relay, the ground for the relay is 7-10 inches into the harness, the ECU/ECM control lead is interupted, [latching relay] at center of dash.

I may install a second PGM-FI Main Relay, hidden in the dash, and leave the stock one in place as a dummy.

Yes, find the black lead, cut it and install the switch, if there are two (2) black leads, they will be on the same terminal, one is the actual ground wire the other is a ground for something else [daisy chane], you must cut both leads and connect them both to the switch, [only one of the cut leads going to the relay is needed] both leads of other cut ends, [harness end] need to be connected together for daisy chane ground to be complete.

Ther is nothing wrong with using relays as kill switches, it's just in the diagram you post it is far too easy to bypass, as mentioned a crook that does not hear the fuel pump prime will try and supply power directly to the pump.

If I was going to use a relay on the fuel pump power lead, I would wire it a little differantly...

The 12V fuel pump "feed" would connect to #87 and #85 the "to fuel pump" lead would connect to #30, #86 would still be the grounding switch, but I would also ground #87a, [not shown on diagram, but found on all SPDT relays] it would prevent a crook from bypassing the kill relay by jumping power directly to the fuel pump because when relay is not "on" the fuel pump feed line is a ground and would result in a dead short if power was connected to it, but still easy enough to bypass by a crook that is not too stupid. 94