2000 Civic Si Master Switch

[backformore]

Great! My first thought was that you were referencing said shows, but I just wanted to be sure!

As for the other, the switch I have does not have normally opened contact or included resistor. Just 2 contacts, a large and a small, that open when the switch is selected off. I was hoping that killing the field current, it would cause the ALT to "turn off" thus preventing damage without needing to "drain" any voltage.

If that is not the case, I will just have to get one of the OMP switches with 3 contacts.

[Greg Amy]

That switch sounds like it will work fine.

The one I'm using has a second circuit that's open when the switch is on. One side goes to ground through a resistor, the other side goes to the chassis terminal of the big red wire (NOT the battery side). Its purpose is to allow any remaining voltage in the chassis to "slowly" bleed to ground when the switch is opened so that the big terminal contacts do not arc. If yours doesn't have that, don't worry about it.

Cutting the field circuit is not for "safety", it's so that the car will stop. Most alternators will continue to product amperage with the battery disconnected, thus the car won't stop running when you disconnect the battery. Cutting the field circuit so voltage goes to zero and/or cutting some ECU power feed wire will ensure the engines stops running when the master turned is turned off.

[itccrx36]

I have the black with yellow wire that powers the ignition coil going through the small terminals on the switch and the large terminals on the switch connected between the negative side of the battery and the chassis ground. On my ITC CRX, normally the only time the switch gets turned off with the engine running is when it is tested in tech. When that happens, I turn on headlights, taillights, brake lights to act as the resistor. I have never had a problem by doing this in the 15 years I have raced this car.

[backformore]

Thanks Will. That is great info. The headlights etc is a great idea. I'd already thought that in a real emergency I don't really care what happens to the ALT so the testing is the only time it matters. Thanks again.

[Chip42]

on our hondas, including a '99 Si (same as your 2000) we always replaced the stock cable from the battery to the starter and main fuse box with a new cable to a switch mounted inside by the left wing mirror. Return cable to the starter then up to the fuse box in the stock location.

Cut the IG1 line from the key switch and run it through the smaller NO contacts on the switch. this will kill the car and not create an alternator issue. and it's easy.

[backformore]

Thanks chip. I thought it looked like it should be that simple, but I appreciate the first hand info. Really wanted to avoid doing unintended damage. Just to clarify, the contacts the IG1 goes through are closed when the Master Switch is ON , and open when it is off. Correct?