most of the battery cutoff switches I've seen are in the dash, under the dash, etc... I can see if you have a battery in the trunk, that makes sense, because it's on it's way to the gear that needs power...
but when the battery is ahead of the engine, it seems you have to double back for a dash mounted switch
I like the front mounted battery to allow for a shorter run to the starter... and removes the need for long run from the trunk area...
thoughts? ideas? things you've done?
On my first Roadster build my battery was located in the rear with the power isolation switch below the center of the dash. With this setup I had to run an additional ground to the isolation switch and then to the car frame. With my current build I have the battery in the front of the car and the isolation switch in the same location as my first build. This set up is more user friendly having the battery located in the engine bay. On both build I increased the size of the wire on both hot and ground cables. The attached pictures are of my build in progress. Attachment 118821Attachment 118822
Not sure about others and interested to hear thoughts. Doing this part of the build currently and decided to incorporate a cutoff switch as well. I am using larger gauge (1) cable and running from the front Breeze battery box to the cutoff switch. Not sure if the increased girth is needed but figured it couldn't hurt. The cutoff switch is located on the lower part of a dash that will extend to the trans tunnel. Still working through the rest of the system.
The run of wire from the switch to the starter is not that long so wouldn’t make a big difference, maybe 2 to 3 feet extra at most. For me it worked out good because I have a main fusion the fire wall that runs my Coyote fuse box that is on the fire wall. So it shuts everything down except my ecu.
I have the Breeze battery box and mounted my cut off on the horse shoe panel under the dash. I pull it when parked somewhere overnight, etc. With the black carpet, you can’t see it, just a bit of security. I did run a bypass to the EFI memory and the clock.
John
Toad,
The horseshoe at the front of the trans tunnel is my preferred location when I build using a battery isolation switch. Yes, it'll add about 3 feet of cable. Let me ask---what is your reason for incorporating a battery switch to begin with?
Jeff
I never use them. Just one more thing to go wrong.
Mike
When I moved my battery forward I skipped the cutoff switch.
I agree with Mike. I build mine with the switch. I sent it to Mike for finishing/painting with the request “if you see something unsafe, installed wrong, or just plain dumb (something that you would not put in your car, fix it or remove it”. He returned it without the switch and I’ve had no concerns.Quote:
Originally Posted by michael everson
Put them in the same location as your factory daily driver.
If you are using it as an emergency battery isolation switch, which is what they are originally intended for, it should be as close to the battery as possible and in a visible reachable location for track emergency workers. That way if anything shorts, including the cable, you can use the switch to get the battery and all of its power out of the circuit.
If you are using it as an anti theft device, they might stop a drunk idiot. They won't stop anyone that knows anything about cars. You can jam a screwdriver or even a stick in and away you go. If you can get to the back of it, you can just move both wires to one post, or short it with a screwdriver. Once the car starts, it runs off the alternator. They make them that use real keys.
I have mine on a shelf in the garage.
Posts #7 thru #12 are why I asked what Toad's motivation is. Unless it is required for racing purposes I don't use them either.
Jeff
But the little key / flag is RED! And red is faster!Quote:
Originally Posted by Jeff Kleiner
i think like most mention, it's a failsafe shutoff - for me it will primarily be for battery disconnect for extended times - but then again, I could probably put a cutoff switch on the + terminalQuote:
Originally Posted by Jeff Kleiner
maybe I'd just be better off using a battery tender in the winter :)
So I had not planned to use one, what is the reason you guys do? Is this a requirement for racing?
Sometimes.Quote:
Originally Posted by BradCraig
Jeff
The OEM's don't use them, so why should we? Having said that, I did install one. I use it as an anti-theft device.
In the trash.
I find my cutoff switch exceptionally handy. I work on the car plenty and shutting of the battery with the cutoff switch instead of pulling one of the battery terminals is much easier.
and where is the switch on your factory car?Quote:
Originally Posted by GTBradley
A bit surprised at all the negative comments regarding a master disconnect. With the right switch, properly installed, certainly doesn't hurt anything if you choose to use one. Not exactly the same as a DD. I rarely open the hood on our DD, let alone work on anything electrical. Plus it doesn't sit hibernating for months at a time. I appreciate being able to shut it down while working on it, storing, being inside a trailer, etc. I don't consider it a security device though. If someone is going to steal one, they're not going to drive it away. It's going to get flat bedded or whatever. At least that's how it works with hobby cars around here. Like I should know. :p
As for location, for the Roadster, I too put them on the horseshoe under the dash. For the Coupe, in a similar location but on the side of the footbox since the front is covered by a switch panel. With the master disconnect in that location, works great for the front Breeze battery location. Also serves as a gathering point for the main power wires from the battery and RF harness, and for the Coyote PDB if installing a Coyote. Often a binding post is used. This serves the same purpose. I'm not a huge fan of the lighter duty plastic versions. Many don't have that high of an amperage rating, plus since I don't consider it a security device, not having a "key" isn't a big deal for me. I've used the Ron Francis MS-1 Master Disconnect on every build. It's a solid heavy piece rated at 180 amps continuous, 1000 surge. https://www.ronfrancis.com/prodinfo.asp?number=MS%2D1.
wow Paul, that switch looks like a beast! :) I may consider that...