KILL SWITCH, AGAIN


#61

OriginalSterm wrote:

I bought the “front” half of the factory cable from a local junk yard (including the small cable and the large one, with the original end on it).

If you don’t have a source near you, I’m sure Bobby @ Strictly German would ship you one.


#62

Just splice the two together? I have the old cable, it’s in great shape, just too short.


#63

I wired mine as shown in this post: http://spece30.com/component/option,com_kunena/Itemid,94/func,view/id,45407/catid,9/limit,10/limitstart,20/#16402

I just put a ring terminal on the cut end of the front half that I purchased, connected that to one post on the switch, and then I pulled the original cable back through the firewall, cut the factory end off of it, and put a ring terminal on it - and connected that to the 2nd post.

Home Depot has a kit to splice two wires of this size together, though, if you need to go that route.


#64

OriginalSterm wrote:

Welding wire is an easy solution.


#65

In my opinion the best solution is to use the forward portion of the existing cable to reach the kill switch. Then use a piece of welding cable to run from the kill switch to the battery. That give you an opportunity to replace the strange BWM battery clamp that is hard find a cover for with a standard clamp that uses a generic flat cover. I prefer solder on clamps, which you can get from wiring products.com.


#66

The existing cable is about 18" too short for where the switch has been mounted. Can I used what looks like a butt connector to add a short piece to the existing cable?


#67

Ok, figured out my first mistake. There is a pair of wires that go to the + terminal on the battery. A really large one and a much smaller one. For some reason, I assumed the little one was for the alternator, poor assumption since it is such a small gauge wire. My plan now is to pull everything off the distribution lug and send that by itself to the switch with 1/0 gauge wire. The rest of the stuff will be bundled together and sent back to the switch with 4 gauge wire.


#68

Now that you’ve seen the small wire, go back and reread the thread and note the consensus that a 2 pole switch is needed.


#69

I have a 2-pole switch. I’ve read the thread several times. I’m pretty sure I either don’t understand, or still have which wires do what confused.

Am I correct in thinking that there is one large wire on the distribution block that goes to the starter and alternator? If so, I plan to connect 1/0 gauge wire to that block and go to the switch. The other smaller wires will NOT be connected to the distribution block and get bundled together and go to a 4 gauge wire and go to the other pole on the switch. After the switch, the two poles join up together at the battery positive terminal.


#70

OriginalSterm wrote:

[quote]I have a 2-pole switch. I’ve read the thread several times. I’m pretty sure I either don’t understand, or still have which wires do what confused.

Am I correct in thinking that there is one large wire on the distribution block that goes to the starter and alternator? If so, I plan to connect 1/0 gauge wire to that block and go to the switch. The other smaller wires will NOT be connected to the distribution block and get bundled together and go to a 4 gauge wire and go to the other pole on the switch. After the switch, the two poles join up together at the battery positive terminal.[/quote]

The big wire does go to the starter and then to the alternator.

What you’re describing probably will work, but it’s harder then necessary. All you have to do is correctly wire the distr block and then interrupt both wires from the battery.

There is a single small wire coming from the wiring harness that connects to the end of the big batt wire at the distr block. The big batt wire has a metal peice on it’s end and there’s a bolt there to put the small wire’s connector on.

There’s also a multi wire (2 I think), that comes from the wiring harness that fasten to a single end connector. This is DME power. It goes to the threaded post that is on the piece of plastic that forms a clamp for the big batt wire. The plastic clamp is just short of the big batt wire’s end. Also on this connector goes the small wire to the battery.

This multi wire provides the DME with it’s own path to the batt.

As long as the distr block is correctly wired, interrupting both wires to the batt will kill the car.


#71

This thread makes my head hurt.
I hope I can get some visuals at Roebling in May (this and firesupprsyses).


#72

doing this tomorrow… expect questions :slight_smile:


#73

thanks to this thread, went without a hitch. used a 6 pole switch from bimmerworld. Used only 4 poles.


#74

Nice and clean. Wtg.


#75

I was thinking the switch needed to be accessible by the driver or the crew outside. After reading this thread I just want to make sure. The kill switch does not need to be accessible by the driver and a installation close to the trunk is ok?


#76

Near the trunk or in the cowl is acceptable. But if you saw my car after the wreck you’d not consider placing the kill switch there. Both areas were damaged to the point that a kill switch would have been inaccessible to a corner worker, if the switch wasn’t destroyed.

Mount the switch (and the fire bottle pull) inside the cage. It should survive a wreck there and still be accessible. I like the switch and pull where the main hoop and harness bar meet. In a like manner make sure the main battery cable is routed inside of the cage. You don’t want it to get pinched between that body and cage.


#77

so i think i have this figured out after staring at my car and re-reading this thread.
I have a 2 pole switch and a mounting bracket on my drivers side a pillar downtube. I plan to splice the big and little wires to the battery in the footwell of the passenger seat area, and run each of these wires over to the switch and back by going behind/under the dash.
If this will not work let me know before I go cutting the wires.

Also, the little wire has a fuse on the wire in the trunk. Do I have to move this fuse so that it is on the other side of the killswitch, or will it still do it’s job where it is?

Much thanks.


#78

It doesn’t matter which side of the switch the fuse in on. I prefer to eliminate the in-line fuse and attach a 60a lug type fuse to the power block in the engine bay. The in-line fuses are frequently corroded by battery acid that has seeped under the shrink wrap.


#79

#80

I’m trying to picture what your saying about splicing. Just to make sure you know the wires can be spliced between the switch and the battery only and each wire must be cutoff seperately by the switch. But if you splice the wires together so that the fuse was between the splice and the battery it would make the fuse useless because the current could easily flow through the large wire. I suggest you keep it simple and don’t do any splicing since you need to use all four terminals of your cutoff switch anyway.