n00b question but, why do all write ups include a relay? Couldnt you just splice in a simple on/off switch and have the same effect? What purpose does the relay perform?

 

My guess is so you dont have a higher amperage wire running long distances...if you have a relay, you can have a turn on/off wire that runs .15 amps (if that, maybe less) that will turn switch the relay on.

 

As long as the lead you cut is low current, .5A or less then just a switch can be used, if it is a high current lead then a switch will have to be big enough to handle the load, add distance to that and even a bigger switch is needed.

A relay is just a big switch, 20-30 amps that can be controlled by a small 1A switch, it is a lot easier to hide a 1A switch then it is to hide a 20A switch. 94

 

Ive found some toggle switches with 30A on them. Would these be what your talking about? So there would be no need for an inline fuse or anything, as long as the switch was somewhat close to the source?

 

What is the switch for? 94

 

Fuel, I was going to keep it within 4 feet of the pump, maybe main relay. IIRC the main has a low volt black wire?

 

A 1A switch will work on the PGM-FI Main Relay ground, it is a low current ground, [less then 250mA].
The ECU/ECM control lead to the fuel pump relay in the PGM-FI Main Relay is also a low current ground, a 1A switch will also work on it. 94

 

lol well I guess my 30A switch is over kill. The fuel one is the yellow wire IIRC for tegs

 

would i need a fuse for the wire?

 

You do not put the switch on the power wire for the fuel pump, you put it on the ground wire for the fuel injector relays coil or the control lead to the fuel pump relays coil.

A fuse is not needed for either one of them.

What is the MM&Y of your car?

The ground wire for the fuel injector relay is black, need the MM&Y for fuel pump relays control lead color. 94

 

its an 01 ITR

 

Injector relays ground is black, cutting that lead will "kill" the injectors, fuel pump, ECU/ECM and a few engine sensor/valves, the fuel pump relays control lead is probably a green/yellow, cutting that lead will "kill" the fuel pump. 94

 

FCM. So what do you do when the main relay has 2 black ground wires? Do you just cut one at a time to see which wire is correct?

 

Simplest is to cut both leads, connect one lead from relay, [cap off the other or remove, it is not needed] to one side of switch, connect both the other cut ends to the other side of switch.

As you should extend the cut leads to the point where switch will be, a single lead can be connected to both leads at cut ends, [solder and shrink tube] to make it easier to connect to small switch, the second black lead is a "daisy chain" ground for something else and should not go through switch. 94

 

does anybody know how many amps the a/c switch on a 95 civic can handle? thinking of ignition to ac killswitch but the switch in the a/c button is very small.

 

The A/C switch supplies a ground to the ECU/ECM through the A/C thermostat, the load is very low so it is unlikely the switch is more then 5A at the most, probably less.

As a relay should be used anyway, the capacity of the A/C switch would not need to be more then .5A. 94