chris11 184 #1 Posted June 3, 2010 Chuck , I need some help on a wiring harness. i have a main battery shut off switch. fuse box a relay im not using a key switch. how am i going to wirer it to the relay to shut it off. or kill the spark??? can you draw some thing up for me? Thank you. Share this post Link to post Share on other sites
Deere Hunter 54 #2 Posted June 3, 2010 Chris, Is this wiring for the Kohler Command? If it is... It isnt to hard to wire up the Ignition. The mags on a Command need to be grounded to kill the spark. Run your wires from the mags to a toggle switch. Then from the switch to a good chassis ground. What you have to remember when the switch says ON, it will be grounded. When it is OFF that is when you will have spark. Wayne Share this post Link to post Share on other sites
Save Old Iron 1,566 #3 Posted June 3, 2010 Chris, sorry for the delayed reply. I was still recuperating from marching in the memorial day parades! I think Wayne is spot on IF you are using magneto(s) and if you only want a MANUAL shutoff of the ignition. If you fall off the tractor, the cutoff switch will stay in the ON position and the tractor still runs without you on it. 1/ update us on the engine your using and the ignition system your using - I ask because your a talented guy with a lot of resources at your disposal, so I have this strong feeling nothing is "stock" in your project. 2/ if it is a simple on/ off you need for the ignition, Wayne provides a simple and elegant answer. If you need something more safety oriented, seat interlock , over rev shutoff / over temp shutoff, let me know. I'll be happy to help you thru a custom solution tailored to your project. Share this post Link to post Share on other sites
chris11 184 #4 Posted June 3, 2010 Its not that simple, im running a relay because of the fuel pump also main battery shut off. rocker switch to turn on pump and a push button to start. and i have the stock dash light to tell me all is on. so i was wiring it with a fuse block and relay. The rocker powers the relay that gives push button power and fuel pump. But when its running i would like to shut rocker switch off with out . and have engine shut off. Thanks Wayne and Chuck. Share this post Link to post Share on other sites
Save Old Iron 1,566 #5 Posted June 3, 2010 Chris, here is a first pass on your description. I'm sure we will refine this. my assumptions are 1/ master battery cutoff will shut off power to EVERYTHING 2/ with rocker switch in OFF position - magneto is grounded and fuel pump has no power applied 3/ with rocker in ON position - ground is lifted from magneto and power is applied to fuel pump. the only part I did not fully understand is "But when its running i would like to shut rocker switch off with out . and have engine shut off" Do you mean you would shut off the fuel pump but still keep the engine running ? Lets talk about that. Share this post Link to post Share on other sites
chris11 184 #6 Posted June 3, 2010 Chuck you showed me the light. I wasnt thinking of the ground on the coil side to shut it off. Thats what i was missing. Thank you my friend. I must be working to hard at work. Thank you for the nice comments too. There is alot of talent all over this forum. Thank you again guys....Ill get some detailed pictures when im done. Share this post Link to post Share on other sites
Save Old Iron 1,566 #7 Posted June 3, 2010 Chris, you are welcome. The only change I would make is possibly moving the "armed" switch hot lead to the terminal #2 on the rocker switch. This would lite the armed light only when the rocker was powering the fuel pump and lifting the mag ground. Remember too, the mag relay is a NORMALLY CLOSED relay - mag kill wire will be grounded by either turning off the master battery switch or turning the rocker switch to the OFF position. A very small wiring change. Enjoy Back to my bagpipe lessons ! Share this post Link to post Share on other sites
chris11 184 #8 Posted June 4, 2010 (back to my bagpipe lessons ) Lmfao where do you come up with that? Thats the way i have to ground it. Thank you Share this post Link to post Share on other sites
TT-(Moderator) 1,131 #9 Posted June 4, 2010 You could also run a DPDT switch with the mag ground circuit on one "side" and the fuel pump (relay?)/starter button power on the other. Power to fuel pump/starter button when switch is in the "up" (on) position and mag ground when switch is "down" (off). If you use a toggle switch, then you can have one of these cool "panic" covers: Share this post Link to post Share on other sites
Save Old Iron 1,566 #10 Posted June 4, 2010 Good point Terry, I thought about condensing the fuel and magneto relays into one DPDT relay. What caused me to think twice about that is the voltage spike or "kickback" of the primary coil when the magnetic field collapses in the magneto. Just like the shock you can get off a points system condenser when the coil field collapses, the kill wire on the magneto probably (I say probably, cause I haven't put an o'scope on one to check this theory) has a 200 - 400volt kickback on the kill wire. If you wire the 12 volt fuel pump and the 200+ volt kill wire in the same physical relay housing or switch housing, the high voltage kickback might jump to the fuel pump contacts in the body of the relay or kill switch. This could be aggravated by moisture in the body of the relay or switch. Unexplained fuel pump failures could be the result. Just thinking out loud here :D Share this post Link to post Share on other sites
Save Old Iron 1,566 #11 Posted June 4, 2010 Another thought ran thru my head just now. With a single DPDT switch or relay, it is also conceivable that the 12 volts from the fuel pump contact could find its way over to the magneto kill wire and there goes the magneto primary coil burned out. We see that happen with bad ignition switches frequently enough. A failed mechanical contactor inside a switch or relay could easily make this possible. I guess I would go with a very high quality DPDT relay or switch if you choose to go with the single switch / single relay method. Share this post Link to post Share on other sites
Deere Hunter 54 #12 Posted June 4, 2010 Chris, Just a thought here, are you gonna be using a "kill switch" on the back of the tractor? I know most clubs require them in case the chain breaks on the sled. I know it can be done but have never wired one up to kill both the mags and fuel pump at the same time. Since I am using electronic ignition on mine I just loop the 12v wire off the battery back to a disconnect switch. If that gets pulled it kills power to everything. But like I say not the same setup as your using... Share this post Link to post Share on other sites
chris11 184 #13 Posted June 4, 2010 Yes Wayne , i have a kill on the back. pull the ring and grounds out mag. What type of ignition are you using? I would like to see your tractor close up. I love the 320 you have. :D Share this post Link to post Share on other sites
Deere Hunter 54 #14 Posted June 4, 2010 Chris, I'm using Dyna motorcycle pickups and coils. Here's a pic of what it looks like. as far as the 320...it uses the stock mags. Are you coming to the show? I should have several of the pullers there. Share this post Link to post Share on other sites
chris11 184 #15 Posted June 4, 2010 Man i love that. Im hoping to make the show. If i can get some paint on this thing i should be there. Thanks for that picture looks great. Share this post Link to post Share on other sites
