When one installs a 'kill switch' to the battery which usually is on the ground side there is a problem. Yes you take the battery out of the circuit but the engine keeps running due to the generator/alternator finding another path to ground. Without the battery load bad things can happen I understand. So, how would you run a switch/relay(s) so the battery gets disconnected and also kill the engine? Thanks
So much for the easy answer but not quite what I was looking for. Let's say I'm racing and the tech inspectors want a real battery cutoff and engine kill switch with one swipe of the hand.
The disconnects used in the video are cheap junk anyway, and should never be used on either side of the battery. Use an enclosed switch with a flag-style handle and a minimum surge rating of 1,000 amps, and connect it to the positive post with a cable. All the race cars I've built used that type of switch because nothing else would pass a NASCAR tech inspection, and they were mounted where a track safety worker could reach the switch from outside the car. Any tech inspector who passes any other type of disconnect should be fired.
"It is better to be silent and be thought a fool than to speak and eliminate all doubt!" - Abraham Lincoln Cringe and wail in fear, Eloi- - - - -we Morlocks are on the hunt! There is nothing noble in being superior to your fellow man; true nobility is being superior to your former self. - Ernest Hemingway Love your enemies and drive 'em nuts!
Not racing for sure. I tinker with street rods and all the guys have the switch like Hotrod mentioned but on the ground side of the battery. After reading prior posts on the no-no of removing the battery from a running circuit of a car I wanted to get mine right. I have a high current relay next to the battery(under the seat/floor board. The switch to control that relay is hidden in the passenger compartment. For me it will be a easy task to change that relay over to the positive side. For the guys with batteries in the engine compartment it might be more complicated. Thanks to all for your help.
I have that same switch installed in the seat pedestal and was also wondering how to properly wire it. Timely information.
The reason I wanted it was to keep the truck safe from theft. Most skilled thieves would know that to defeat the negative side switch, a jumper to any ground would all that would be necessary. The positive side is harder.
The relay is an electric switch if you will. Below the floor board under the seat is not a place many would look I guess. The switch is also in a hard place to spot...ssssh, I'm not telling.
Instead the the high current switch we have been talking about, I installed a high current relay in place of the switch. Does the same job but can be operated remotely from the passenger compartment or if you wish from several places.
Check out the specifications of the disconnect switch I listed. It has a low-current set of contacts to isolate the alternator output if it's wired correctly. That prevents feedback to other circuits to avoid the run-on situation you described. Jerry
"It is better to be silent and be thought a fool than to speak and eliminate all doubt!" - Abraham Lincoln Cringe and wail in fear, Eloi- - - - -we Morlocks are on the hunt! There is nothing noble in being superior to your fellow man; true nobility is being superior to your former self. - Ernest Hemingway Love your enemies and drive 'em nuts!
I have that exact switch and the plan is to put it in the center of the seat pedestal (front) so I can reach down and switch power off to the truck en masse. I was going to use the Negative side, but now that I am learning it's too easy to defeat, is it as simple as just switching from left brain to right brain and just connecting the switch to the Positive side of the battery?
Proper "kill" switch, grounds the ignition. No spark ever. Battery cut out is best on the positive side, for reasons posted above. To stop the engine and cutout the battery, just hook the ignition to the cut out switch. Switch off, no power to the ignition. Switch off no connection to the battery. Racing is a different game. protecting the truck, that is a good one to play.
