Race Kill Switch problem
 

I switched from a four cylinder to a 2.0/6 in my 914. The POs red flag style kill switch mounted above the engine bay is wired into the POSITIVE circuit.

When swapping out the electricals and such I hooked it up as the PO did and did a test over the weekend.....revved it to 2500 rpms per the tech rule book and turned the emergency cutoff key to OFF. It dipped a bit in RPMs and then returned to running. Obviously a fail.

I'm thinking that the the three wire alternator needs to be hooked thru the switch as well? Either the D+ or the more likely the main?

Anyone have a wiring circuit diagram for it?

Stock Porsche CDI box, 2.0/6 "S" motor....

I had a "similar" issue with the dash ignition on an another car that needed a diode on the D+ to get it to stop when the ignition was killed...don't think this is the same.

TIA

Mike,

Search here. Hopefully you didn't destroy your alternator in the process.

The six pole switch has the following contacts

1 fat pair, for the battery positive lead
1 small pair, normally closed, for the ignition circuit
1 small pair, normally open, for the alternator dump resistor.

When you throw the switch the battery gets cut off, but the alternator still provides power, which is why your engine didn't stop running. Except that when the electrical load (the battery) is removed the alternator voltage and amperage spikes OFF THE CHART. This is why the wiring diagrams say "Operation of engine with battery removed results in immediate destruction of alternator."

With the six pole switch, when you throw the switch, the battery and ignition are cut and the alt poles are CLOSED. One of those poles is connected to the positive battery terminal on the same side as the alternator. The other one is connected to one terminal of a 10 ohm, 100 watt resistor, and the other to ground. When you throw the switch, the current from the alternator gets shorted to ground through the resistor, which is providing the load.

Be careful, don't burn the car down! Good luck!

Where do they sell the 6 pole safety switch?

The two pole safety switches do not work? I noticed that they are conneted between the battery negative and ground, but the effect is the same, if actuated the engine does not stop.

Thanks for your help

Great....is it immediate? I switched it back on after about 3 seconds....

Guess I will have to get the multi meter out.

painless wireing sells a relay kit to do the same thing as the multi pole cutoff switch. look in jegs or summit or painless wireing.

Well I didn't kill the alternator.....checks out as charging....so the dual post kill switches won't work or are illegal or just junk?

Just junk. They are useful in dirt-track cars that don't run an alternator.

Well no harm no foul....who makes a good one?

Sparco.

Mike-smart racing has one of the 6 pole #'s for 44 bucks, or you could do the relay- the kit is 40 bucks, but if you're creative with parts I think you could put it together for half that.

No need to run the Alt resistor. Just connect the battery cutoff through the positive side, as you described, and on the other contact run a wire (in series) to the ignition (dme relay or such) and you're done. What you're doing is causing the engine to shut off when you flip the switch, by A. shutting the battery off, and B., shutting off the Ign. And that way, the alt cant keep the car running.

So run the big wire from the alt thru the switch like the paostive battery terminal?

What they suggested on 914 club was to do that-run a seperate wire from the alt to the battery side of the switch, so that when you hit the cutoff the alt still sees the battery as a load and doesn't spike. That should work, but if your cutoff is on the front cowl that's a fair amt of wire-at least in my case, where my batt is located in the former gas tank space and the cuttoff is near the driver's a pillar. Where does the alt output go now, to a starter pole?

You'd also need to make sure that the only way that the ign sees voltage is thru the cable on the cutoff out side.

It's on top of the engine bay, above where the battery used to be....

The resistor is $1 from Radio Shack. I would not recommend running a separate unfused wire through the many nooks and crannies of the car. Remember that one of the purposes of a kill switch is to isolate the electrical system from the car to prevent sparks in the event of a crash. You back it into the wall, you have fuel leaking all over the place, the corner worker runs up and isolates the electrical system from the whole car with the exception of a 12" run from the battery.

Battery is in the passenger seat area. The run is no more than 2 feet.

Matter of fact....wouldn't it make sense to kill power to the coil?

Been looking on line for a schematic...no luck.

Mike-look at smartracing's instruction page-it gives you a good idea of what the six pole does. What you might want to do, given the proximity of everything is run the alt lead to the "in" side of the cutoff, along with the lead coming from the battery-currently it isn't isolated in this fashion-while I don't know how your car is currently wired (why I asked above where the alt lead runs to now) it likely runs to a point common with the main lead from the bat to the starter, which is why cutting off the battery only isolates the battery-the alt is on the "out" side of the switch, along with the ign and the starter primary-if you isolate it to the "in" side of the switch, the batt provides a load to the starter and the alt is removed from the ign as well. Capice?

Still haven't mounted those darn Deltas I bought your bike to get...

THAT'S WHAT I WAS LOOKING FOR....the stoopid book.

Thanks.

BTW....it says to hook the coil into the cicuit and have a resistor to ground....nothing about the alternator.

Yah-if you have a six pole switch to begin with....
If you wanna utilize the 2 pole you have, you need a relay to dump the alt when you open the switch, or you need to isolate the alt feed to the "in" side of the switch.

Gonna take a closer look at the switch I have...the four "other" poles seem pretty small and easy to overlook.

Looks to be a crappy two pole....crud.

This looks like the one I have....

http://forums.pelicanparts.com/uploa...1115080469.jpg

No matter how you fry it...pun intended???.....this is a place where you don't want re-engineer the wheel and gat fancy about it.

First, the switches are notorious peices o' crap. Get a good one because:
The last thing you want is an internal issue or a connection issue frying the alternator, or wiring etc, and the next to last thing you want is the thing to suddenly go down on you with the "2 to go" signal on grid.

Smart Racing has the best solution, and you can move on to other more important issues

How about Flaming River....they are the ones sold at Summit Racing.

I got mine from TRE, of this board..

It came with the alt resistor, (which you dont need if you wire up an ignition cutoff as i mentioned earlier.)

Well, I agree that if you cut the ign only the car won't run for long, but the alt is live as the engine spins down and I'm not sure the diodes like that, which is why the six pole switches both cut ign and provide alt with a load. Particularly big deal on a 914-6 where a fried alt means an engine drop on top of the alt expense.

I have a question.
If you do the connections like the Smart Racing diagram, will you have always a current flowing if the Switch is left in the off position?

Just ordered from TRE....

>>Well, I agree that if you cut the ign only the car won't run for long,<<

Uhm it wont run at all. Its instant.
I do understand the arguement of the Alt, but thats because most people dont wire in an ign relay cutoff. Pull switch and car cuts off instantly. No coil output., no run. Its doing the same thing as if you turn off the ignition key.

FWIW, apparently the factory knew how to do it with a 2-pole.

http://www.pbase.com/9146gt/for_sale_bosch_kill_switch

Its sort of the same thing as if you turn off the ign, but if you turn off the ign the alt still "sees" the bat as it spins down, 'cause its on the same terminal as the battery main-I understand that we're splitting hairs, but better safe than sorry.

The two pole works if you isolate the alt from the ign by running the feed seperate. John raises a good point about a long unfused run of wire, so I'd put a resetable 40 amp breaker or something inline close to the alt.