longhorn911

I’m installing a new 6 pole kill switch and am having trouble deciding which wire to tap into to connect to the pole set marked as “2” in the diagram below to cut the ignition. I’m sure I could go after the DME or ignition relays, but they are rated at 25 and 30 amps and I read somewhere that the smaller pole sets (“1” and “2”) on this switch might not be rated for that high of a current. What wire have others used with this switch to kill the ignition?

speedoflight

split the thick red w/ green stripe wire in the junction box behind firewall and wire it to the poles. works well. there's a thin one too. not that.

Dave DE

A little more info on the red/green wire. Looking at the wiring diagram, I think the junction box is also known as the Current Distributor. There are small and large red/green wires attached to F5, which is labeled Engine Electronics. It looks like the large wire powers the fuel pump, ignition relay, and injectors.

Current ratings:
F5 is rated at 80A. It feeds the fuel pump 25A fuse, CU alarm 15A, Ignition relay 30A, MFI 25A.

I didn't hook up my shutoff switch, so I can't make any recommendation. Just thought I'd provide some technical details to try and help.

longhorn911

Thanks guys. However those current ratings are really high in comparison to what I think I read pole set "2" on the switch is rated to handle. I cannot find a definitive max current spec on that switch anywhere, however I did read a post on a BMW forum where the author claimed that the instructions that came with the OMP version of this switch stated that pole set "2" has a max rating of 5 amps. I'm sure this wire is a great one to use, but don't want to risk burning up the switch. It could be that the poles "2" are rated much higher, but I cannot find anything definitive on it...

Dave DE

Keep in mind the fuse ratings are usually a lot higher than the nominal amount of current being drawn. Once you identify a wire you would like to use, I suggest measuring the current in that wire while the engine is running so you know what the switch will have to pass.

longhorn911

Good idea - I'll do that. Still trying to hunt down the actual rating though just to ensure I don't create a safety issue (or burn up the switch and shut down the car)