Cut Off Switch

[rcb]

Greetings MVers !! I want to install a cut off switch on my M925. I am running 2 batteries and
not sure where to install the kill switch. The choices are in between, the negative, the positive,
or positive / negative on the jumper cable. Your collective thoughts, please...
Bob
Pittsburgh

 

[73m819]

install in the ground before the frame

 

[TurboMustang370]

What switch will you be using?

 

[M35A2-AZ]

This is what I did on my M923A1.

 

[papakb]

That switch looks awfully light duty for a large truck. Are you only switching the power to the ignition and accessories? That switch would be OK for radios or accessories but not much more. Starters pull massive currents and need switches with substantial current capabilities. If you want to be able to fully disable the vehicle you want a switch that'll handle at least 100 amps. Cole Hersey makes some excellent battery disconnect switches here: http://www.colehersee.com/home/grid/cat/207/

The best place to mount the switch as stated above is between the negative battery terminal and the frame. That way if your wrench touches anything during installation it won't trigger a light show.............

Kurt

 

[73m819]

Best way to see if a switch will handle the load, start the truck 1/2 dozen times, check to see if switch warm

 

[M35A2-AZ]

That switch looks awfully light duty for a large truck. Are you only switching the power to the ignition and accessories? That switch would be OK for radios or accessories but not much more. Starters pull massive currents and need switches with substantial current capabilities. If you want to be able to fully disable the vehicle you want a switch that'll handle at least 100 amps. Cole Hersey makes some excellent battery disconnect switches here: http://www.colehersee.com/home/grid/cat/207/

The best place to mount the switch as stated above is between the negative battery terminal and the frame. That way if your wrench touches anything during installation it won't trigger a light show.............

Kurt

Kurt, The Colehersee switches are what I am using in my trucks, I have been using them now for a year or so with out any problems.
they are rated at "Electrical Ratings 1000A,175A continuous".
The switch just looks little in the battery box.


Flaming river also has some good switches.http://www.flamingriver.com/batterydisconnect

 

[TurboMustang370]

Kurt, The Colehersee switches are what I am using in my trucks, I have been using them now for a year or so with out any problems.
they are rated at "Electrical Ratings 1000A,175A continuous".
The switch just looks little in the battery box.


Flaming river also has some good switches.http://www.flamingriver.com/batterydisconnect

How much do those "Colehersee" switches go for?

 

[M35A2-AZ]

They run around $50-65.

 

[TurboMustang370]

Awesome! I'll add that to my list.

 

[Cleveland Iron]

FYI: The reason for disconnecting the ground from a battery in a battery box is mechanical safety. By isolating the batteries from ground, accidental grounding any part of the power side of the batteries will have no effect. Useful when tightening battery cables with steel tools.

Normal electrical / electronic switching should still be done on power side.

 

[TurboMustang370]

With a setup like photographed above, will that work as an "anti-theft" setup? Will the keyed switch on the negative side prevent the vehicle from being started?

 

[steelandcanvas]

Yes, as long as there is no negative going to the frame, the starter and solenoid don't see a complete circuit.

 

[papakb]

Looks like your good to go then. I just hate to see electrical problems/fires because they're PITA to clean up after and there are so many people who just don't understand electrical issues.

Merry Christmas,

Kurt

 

[M35A2-AZ]

Yes you can not start it with out the key. But you can short the switch out and get it started.
But that would take a little time and you would have to know about it.

 

[M35A2-AZ]

Looks like your good to go then. I just hate to see electrical problems/fires because they're PITA to clean up after and there are so many people who just don't understand electrical issues.

Merry Christmas,

Kurt

Kurt you are right fire "BAD"..