Hey guys, I'm getting GRM Project MINI Cooper S http://grassrootsmotorsports.com/pro...mini-cooper-s/ready for the track, and the master kill cutoff switch is creeping towards the top of the list. In the back, there are two big honking red wires coming off the positive terminal on the battery. Which did you intercept for the cutoff (one runs along the driver's side sill inside, the other along the same sill but under the car), and where did you pick up the alternator for the kill switch? I'm planning on mounting it off the cage just near the drivers side window so both I and corner workers can get to it if need be. Thanks for your thoughts!

 

Scott,

You have to cut both cables at the battery. One runs to the Starter the other to the fuse block under the hood and feeds the ECU.

I have since modified the cut off by breaking the run(ignition) wire(red) from the key. By breaking both battery cables and the run wire from the key you'll get a complete shut down and pass tech with no problems. Leave the switch on and use the key for daily driver. Turn the switch and all power is cut from the battery and ignition is cut and engine stops. If you have any question PM me I might have my diagram of what I did.

I believe I say one of your post on the NASA boards for PT. I run PTC in So CAl as well as USTCC on the west coast.

Looking forward to seeing you out on the track

 

Rich, thanks for the reply, I appreciate the help! Where did you locate your cut-off switch that you were able to intercept both big red cables, or did you do some extra routing? Another option is one of the remote solenoid cut-offs, but I kind of like the idea of a hard-wired old-school switch.

And when you say "from the key," do you mean from the small wiring harness block that's attached to the opposite side of the key hole on the ignition cylinder? Photo attached for clarity:





Sorry for the newbish questions, but I'd like to clarify both for myself and for any future MINI racers who are building cars.

 

Scott, That's correct as to the block, I would want to check which wire again and will have to get the book out. It's about a 10g wire. I mounted the switch to the tunnel next to the ebrake Some I've seen are mounted to the roll cage next to the passenger window. Easier for safety crew but harder for the driver to get to. See thumb nail below. I ran both battery cables to the switch and two away. There's a lot of amps flowing when starting. You could also up the sizing of the cable for the first run to the switch. It was just as easy to cut and solder new lugs. Use the switch with battery connections and ignition connections.


I first went with the remote solenoid cut-off. A lot more work. And if you want to use as a daily driver, the solenoid draws amps when on. So if you turn the car off with the key, in a short two day no more battery.

This pic only shows one cable going to switch as I have since modified the location of the battery and have shortened up the cable.

 

Nice setup on that switch Rich. Good to hear your still around also!

This is where we put it in snids cooper.



Scott, you have a floor in that car? Looks like a nice car. Show more.

 

Greg, I thought about that position, but with my seat mounted all the way back and the harness on, the position is to hard to reach.

Have you gotten your beast out on the track yet this spring?

 

For worker access I'm going to mount the switch where the air vent to the left of the steering wheel used to be, I'm hoping I can intercept the two big red cables coming off the battery around the driver's side footwell (the one running in the interior will be easy, the exterior cable will probably require a bit of creativity, I may re-route it from the underside to the interior so I only have to go through the firewall once.

No more floor, although I do have a nice aluminum plate for the driver's side footwell, including a dead pedal. The latest pics are always up at the GRM site http://grassrootsmotorsports.com/pro...mini-cooper-s/

 

A quasi-dumb question for ya: at a glance, there are two red wires going into that block (I'm at the office, can't check to see if one has a stripe). Are they part of the same circuit, or do I need to choose one red wire over the other?

 

Scott,

I am sorry to say, I could not find my notes, or find it in the manual. Also my wiring harness is all tie wrapped up in place. I'll try to get a pic this week end or find out what wire it should be. I was going to install in the vent as you described but my cage bar that the steering is connected to interfered with the back of the cutoff switch

I believe the larger of the two is the hot that feeds the starter/ignition switch. Meter it and find out do you have 12 V at that wire if the key off. You will want to cut and splice the other red wire that shows 12v after the key is turn on. That is the one to run to the cutoff switch. The switch or key will kill the ignition.

Best of luck.

 

No worries, I got it figured out, the car now has a functioning kill switch. I'll post the details pretty soon, we've got some catching up to do in the Project Car update page, so the most recent one is about the cage. That qualifies as driver safety as well, check it out here:
http://grassrootsmotorsports.com/pro...ields-maximum/

 

I found 12v switched power at both of the red wires, oddly enough, and so I picked the closest one and snipped it; that did the trick. A full story with photos will be up pretty soon at the GRM MINI's project car at http://grassrootsmotorsports.com/pro...mini-cooper-s/

In the meantime, check out the steering wheel lock defeat thread that just went up.

 

Scott,

Thanks for the mention in your story on GRM MINI battery cutoff switch.