How do I isolate the coil?
 

Ok gang, finally getting around to installing the new odyssey battery and 6 pole cutoff switch and I can't figure out how to isolate the coil on the NC contacts. I think I've read all the threads that say "do it" but haven't seen in writing how to actually accomplish this. Seems the alternator is protected via a supplied resistor that goes to ground, but I'm stuck on the coil.....HELP, and thanks ahead of time!

I would also like to know how to cut the power to the coil. When I installed my cutoff switch I cut the power to the fuel pump. It was easy but the engine sputters for a few seconds before it shuts down.

Well, you have a +12V wire that goes to the coil, right? Can't you just run that wire to the switch, then run another wire from the other side of that switch contact to the coil?

Maybe I'm oversimplifying the problem, but I think that would do the job.

--DD

Unfortunately the coil is in the back and the switch is in the front by the battery. I would rather not run a wire from the back to the front and then back again. Is there an easy path? I might consider this if there is.

I would think that if the main terminals of the cut-off switch break connection in the main red cable to the battery then you have succeded in cutting power to the coil, and ignition, and fuel pump, and...

Tim, my thought is to do what you did and just cut the fuel pump....

Dave, you've got exactly the right idea, but as Tim said the logistics are all wrong. I am thinking there may be a way to interrupt a lead from the ignition switch to the coil and that would do the trick and it is much closer than the coil itself. So the question is which lead from the ignition switch goes to the cd box/coil....

Jamie, I thought the same thing, that disconnecting the battery would kill it all, but several instruction sets I've seen specifically say to isolate the ignition system.

You can take the battery out of the system--the car will still run on the alternator. Seen it a bunch of times. (NOTE: running like this can damage your alternator or some of the other electrical components on the car!!) If you want to kill it dead, you need to interrupt the power to the coil or whatever your car is using to trigger the sparks and/or fuel.

I'm not sure which wire it is that you need to interrupt. It's in there somewhere, though. I can't tell from the wiring diagrams.... :(

--DD

Dave, I've heard the same thing about the car continuing to run and that is why I suppose you want to kill the spark immediately. I've stared at some Haynes diagrams and a buddy stared at the Bentley version and we were still not sure how to kill the cd box. We thought power may come from one of the fuses up front, though it is not labeled, but pulling fuses didn't work. So, I think next may be to work at the ignition switch itself and hunt for the wire that powers the cd box...

GOT IT!!!!!

OK, here ya go! On the fuse box up front at the fuse labeled Backup lights (S11) is the apparently infamous cd box power lead. The top of the fuse panel is the hot side and it is here that the power comes from. On my car, there were two red leads at this terminal. One jumps across to another terminal and the other was trailing behind the fuse box and down into a wire loom. The wire that went into the bundle is the one that I split to eliminate power to the cd box and hence the coil.
It was obviously the correct wire because after it was cut the box quit humming with the ignition in the run position. Also the factory wiring diagrams show this to be the only red wire in the harness that connects to the cd unit.

So here's one for the archives since no one else seems to have shared this previously! Of course your car may be different, but I ventture to say that all SCs at least are the same....