Main electrical power shut off

Skidkid · Mar 12, 2014

Question I have is, should I kill switch main battery power on the negative side or positive side?

RustyC · Mar 12, 2014

The CAT tractors that I work on use a disconnect switch on the ground side. I don't know their reasoning behind it. I have noticed that CAT uses circuit breakers or fuses near the battery B+.
With the breakers and fuses one the B+ side and the disconnect on the ground side, the only part of the circuit not protected are the large cables near the battery.

Both of my rigs are using disconnect / main power switches on the ground side, no issues.

patooyee · Mar 12, 2014

I've heard ground side is best so that you can't end up in a situation where the positive cable leading TO the switch shorts out leading to a scenario where the short can not be disconnected. With the ground being switched everything looses ground, even a shorted main + cable.

kmcminn · Mar 12, 2014

I have been thinking about this today seems as though there are pro and cons to both. I am going to try to come back with an educated answer tomorrow.

hjpcummins · Mar 12, 2014

Re: Main electrical power shut off

I run on the hot side.
Just made sense. But I don't matter either way

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4byfan · Mar 12, 2014

Got one with it on the ground side & one with it on the hot side. Can't really tell any difference.

TBItoy · Mar 13, 2014

On the Gremlin I used a BlueSea 500A disconnect to break the + side up at the front of the truck (battery is in the back).

Mainly I did that so I could used the switch as a junction block and hook my winch, starter, main harness +, and alternator wire to it.

I grounded the battery directly to the frame in the rear, and grounded the engine and winch to the frame in the front (welded a 3/8" bolt to the frame to make a stud).

Neal3000 · Mar 13, 2014

Positive side is what ultra4 requires

Skidkid · Mar 13, 2014

I may have to do the + side as the LS ECU requires constant 12v supply.

How well will a main power shutoff switch handle the load of a winch?

TBItoy · Mar 13, 2014

Re: Re: Re: Main electrical power shut off

Skidkid said:
I may have to do the + side as the LS ECU requires constant 12v supply.

How well will a main power shutoff switch handle the load of a winch?

Just make sure to get one rated for big amperage. Over 300 at minimum according to what winch you have.

Skidkid · Mar 13, 2014

Re: Re: Re: Main electrical power shut off

TBItoy said:
Just make sure to get one rated for big amperage. Over 300 at minimum according to what winch you have.

Warn 8274

bushhog750 · Mar 13, 2014

I did away with the 4 solenoids that run my 8274 and have replaced it with a 500 amp breaker. It pulls all day and has never give me any problems. I'm not 100% positive but I'd say using a 500 amp disconnect would run your winch, and other accessories just fine.