Forum

This is a new rule which last year was decided to be added for 2009. It seems there is support for this, but we need feedback to help decide the finer details.

Something that hasn't been discussed much thus far, is whether an isolation switch should be required for winch batteries as well as the main car battery, or not?

I don't believe that one switch to contol everything is realistic. A case in point is my truck where I have 12v and 24v systems. I do however have independant kill switches for each winch motor and also for the truck, and it isn't a very expensive exercise to make this work. The switches are no more than $120 each (600amp rated) and it just means a few extra cables which if they are big enough won't cause power drop either.

So separate switches for each battery is the way to go, but should we be requiring that people have isolation switches for the winch batteries as well as the main car battery?

An isolation switch should render every electrical system in the vechicle inoperable - other wise whats the point?

The idea is to have a very big easy to use switch that will stop the truck in an emergency. While having one swicth trn everything off is the best option, you also need to be practical about the application. I don't see any reason why you having seperate switches is a bad compromise.
We are talking about a kill switch that will stop the engine and the vehicle electrical system. We are not talking about auxillary electrical systems, ie 24v for winches, as these are by there nature very isolated. I think you would be silly not to have a switch on your winch. Wait untill you weld a solenoid shut and can't tun the winch off! It isn't going to kill anyone but it will break something that is for certain!

A single isolation switch should shut down the entire electrical system, not just part or parts of it.

John and Garry Walker hit a tree at Rotorua in 2004 (or maybe 2005), something shorted out (presumably solenoids stuck closed) and a fire started.

Steve Hudson’s truck had an electrical fire at Denny’s 2003. They couldn’t disconnect batteries fast enough to stop it from becoming toast.

That was Dad and I Mitch in 04, and it was the switch on the front that shorted out. Our sparkie did us a dis-service there as it was the only switch in the car that wasn't fused. Had it been fused we wouldn't have had that problem. Although yes, an isolation switch would've also saved us some drama for sure.

There ya go. First hand experience on why the isolation switch should shut the whole truck down.

Winch isolation is a better idea. MY car key still turns of my truck . At the last comp my isolation switch which runs my twin batters for winching went mad and tryed to boil one of my batterys and if it had been a std wet cell it would have exploded when disconected at the posts. I run isolation switchs in reach of both driver and co. It gets my vote. Cheers Klembo

Just because an electrical fire is a possibility doesn't mean we need a rule to try and cater for it. As Jeremy said, If their switch had a fuse there wouldn't have been an issue. There are too many ifs and maybes. Are we going to insist on a fuel cutoff switch in case of fuel fires? What about a driver cutoff switch?

there was some debate at the last meeting regarding the working of a kill switch and what it should do, the following is taken from oranz rules. it does get a bit messy once you factor in 12-24 volt systems and electric winches but as darin has said it can be done. these rules show what should be done!

(d). All vehicles must be fitted with a battery isolator / kill switch. When operated isolates the total electrical system including the ignition and charging circuits.
This switch must be clearly marked with a red surrounding triangle approximately 75mm x 75mm with the ON/OFF positions clearly marked and in reach of the driver and navigator when strapped in and its position must be clearly identifiable from the outside of the vehicle.
(e). All systems shall be fitted with an ignition ON/OFF switch in reach of the driver when strapped in. The battery isolator / kill switch may be used as the ignition switch.

CCDA rule is probably a lot closer to what we should be doing. As below.

4.4.11 ELECTRICAL

A battery mechanical isolation switch for the battery that provides power to the engine, ignition and

fuel pump shall be securely mounted within easy reach of each member of the Crew and this

switch may isolate the negative terminal.

The old htread that has some previous discussion and may help clarify things.