Locating a battery cut-off switch

[Alpine 1789]

Fooling around with my ammeter has (I think) finally gotten me to the point where I am ready to install the battery cut-off switch I bought several years ago. It is a Lucas switch, which will have approximately 2" sticking out below whatever installation point I choose.

I am looking for a location that is 1) easy to reach; especially in an emergency 2) easy to install; meaning easy access to the primary wire and 3) safe; the last thing I want is for this to result in a short - I want it to prevent one!

Looking around, the best place I can see is just to the driver's side of the battery box, which would locate it above the prop shaft. It looks like there would be plenty of room for clearance (I plan on using rubber boots over the connections, just for safety) and the wire access there would be a breeze. Are there any better locations that I am missing?

Thanks.

 

[alpine_64]

Jim,

My fathers car has it located on the front face of the vertical panel behind the seats that intersects the floor and the rear parcel shelf. The seat hides it from sight, it locates it in the car and acts as a good security device (well it did till i just told everyone now..

 

[ozzie alpine]

Jim,
Any reason why the cut-off switch couldn't be on the earth cable, rather than the live? Less risk of shorts this way....
Dave

 

[Nickodell]

Jim, to echo Dave; put it on the ground (earth). Once it is turned off, it is impossible to get a short. The farther away from the battery it is, the less use in preventing a short/fire. Mine is on the battery ground terminal itself, but the switch key (removable) is located above the rear "seat," so you can actually locate and turn it off while seated in the driver's seat. I'll post a picture after the holiday. It's an American celebration of some kind

 

[Alpine 1789]

Thanks guys. Mounting it on the ground would certainly be easier. I just assumed there was some reason not to do it. I'll be interested in seeing your picture, Nick, but not having to locate it along the main wire circuit may free up some additional options.

The only problem I can see with doing it this way is that I wanted to run a separate power line for the clock. I suppose I can run a separate ground wire for the clock, but I'll have to be careful to isolate the clock from everything else.

 

[AlpineIan]

Jim,

My advice is to mount it somewhere where you can reach it from the drivers seat easily. It's a pain to get in the car and be all ready to go and realize you have to get out and unbuckle to turn on the switch!

 

[thequick]

It has been my experience, that depending how the alternator is wired, the car will continue run if + side of the battery is disconnected while the car is running. The alt will provide the potential.

The question arises, what are you using the switch for? Are you trying to keep the car from starting or stop the car while it is running? I have wired my switch to the neg side of the battery because it cuts the power completely.

 

[Alpine 1789]

I primarily want it for safety. I like the idea of being able to quickly and easily disconnect the battery when I'm not using the car. I have quick disconnect cables on it now, so its not that hard, but a switch would be even easier. Especially, as Ian notes, if I could reach it from the driver's seat.

 

[Nickodell]

Hi, Jim. This is my setup. The switch I use is the kind with a removable plastic key. The switch itself is mounted on the negative battery post, by cinching one of the switch terminals to the post with a hose clamp. I know that sounds rather Rube Goldberg, but nothing else I tried to use worked, and it has worked fine for over 7 years. As you tighten the clamp the threads on the switch terminal bite into the soft metal batt. post. You can't move it even by brute force once you tighten the clamp.

The stem of the switch (the part the key goes into) goes through a hole in the battery box lid, and there is a 5/16" hole in the rear deck carpet allowing the key to be inserted

The beauty of the arrangement is that you can reach back and turn the key ON or OFF without even having to look round, and when parked for more than a couple of minutes the key goes off, preventing any chance of an electrical fire. It would also isolate the entire electrical system in the event of a short while driving.

When parked away from home I take the key with me, making a first-class antitheft device (it's unlikely that a carjacker would be carrying a grounding cable and tools to attach it to the frame).

 

[Jeff Scoville]

The beauty of the arrangement is that you can reach back and turn the key ON or OFF without even having to look round, and when parked for more than a couple of minutes the key goes off, preventing any chance of an electrical fire. It would also isolate the entire electrical system in the event of a short while driving.

Are you saying when parked, the key turns itself off automatically?
I have not seen this type of switch.
Sounds interesting.

 

[Nickodell]

Are you saying when parked, the key turns itself off automatically?
I have not seen this type of switch.
Sounds interesting.

Sorry, I was ambiguous there. I mean I turn it off. I got the switch from Harbor Freight, at about $3, but they are also available elsewhere. The more familiar switch, with the knurled non-removable knob, is made by Lucas I believe.

Lucas........Electrics.......Aagh. Would probably fail just as you need it.