Factory dual batteries...which cables do I pull to "disconnect the battery"

[AJMBLAZER]

Funny how the Chilton's doesn't seem to even mention dual batteries.

What's the correct procedure to disconnect the batteries?

One of the previous owners was a amateur radio enthusiast and I have wires running all over the place. Just discovered a positive and negative wire running from the d-side battery into the cab and just laying under the carpet. Luckily the ends are capped off...
Looks like when this person sold the truck they pulled all their stuff off in a hurry.

 

[cybrfire]

Pull the ground cable off the battery that is hooked to the starter first. then the other ground if you have accessories hooked to that batt. as well. Then the positive cables.

Doing the grounds first will prevent an accidental wrench into the fender shortage.

 

[moneypit_K5]

forgive my potentially ignorant question, but why does it matter what order they come off? I always just unhook both hots and call it good.

 

[cegusman]

forgive my potentially ignorant question, but why does it matter what order they come off? I always just unhook both hots and call it good.

If you would have read above

Doing the grounds first will prevent an accidental wrench into the fender shortage.

 

[Stomis]

forgive my potentially ignorant question, but why does it matter what order they come off? I always just unhook both hots and call it good.

Because the ground is everything. Everything has a charge with the ground wire on. The only thing that you can short to disconnecting the ground is the positive terminal or some sort of open pos wire. When disconnecting the pos you can short to anything metal.

Theres also some text book battery gas dissipation BS that never happens that they taught at school too.

 

[moneypit_K5]

interesting. not sure why im not more clear on this. in my mind, if the pos is unhooked, then there is no more current through the truck because all the pos current comes from the battery. So aside form hitting the pos terminal with a wrench, I dont see any way anything could be shorted out.

I just learned something.

 

[Stomis]

interesting. not sure why im not more clear on this. in my mind, if the pos is unhooked, then there is no more current through the truck because all the pos current comes from the battery. So aside form hitting the pos terminal with a wrench, I dont see any way anything could be shorted out.

I just learned something.

Actually in contrast in automotive wiring the negative flow of electrons (which when handling electricity is the hot side) actually comes from the ground. The energy flows through the chassis/ground wires and returns in the positive wires. It really makes no sense at all why they would call ground ground and hot hot. I've been through this with a couple GM cert'd techs/teachers at my school and they agree the labeling doesnt make sense.

But your right once the positive is off theres really no danger. The only point really is that when unbolting that pos terminal if you smack that wrench on anything on the body its gonna arc where as the negative term can only arc to the positive terminal.

 

[dhcomp]

Actually in contrast in automotive wiring the negative flow of electrons (which when handling electricity is the hot side) actually comes from the ground. The energy flows through the chassis/ground wires and returns in the positive wires. It really makes no sense at all why they would call ground ground and hot hot. I've been through this with a couple GM cert'd techs/teachers at my school and they agree the labeling doesnt make sense.

But your right once the positive is off theres really no danger. The only point really is that when unbolting that pos terminal if you smack that wrench on anything on the body its gonna arc where as the negative term can only arc to the positive terminal.

Yep, when you start learning about circuits, it is clear that there was no good reason to give people the idea that flow comes from the positive side. Electrons flow from the negative side of the battery.

 

[6.2Blazer]

The quickest way to just kill power to the truck (assuming the battery cables are still routed in the OEM way) would be to pull off the passenger side positive terminal, making sure the positive cable coming from the drivers side battery is disconnected from the cable going to the starter. This will kill all of the power to the truck. Just remember that the cable end coming from the driver's side battery is still hot.

But as mentioned before I would probably disconnect the grounds from both batteries (you have to do both or it won't kill the power) if I was doing electrical work.

 

[dhcomp]

Am i the only one who Almost never disconnects my battery? Most of the electrical i do requires testing, and you can't test dead circuits, so i've gotten pretty good at working hot. Its only 12 v, right? Most of my stuff involves trailer wiring, stereos, or alarms.

Plus, how do you listen to the stereo when you disconnect the battery?

 

[AJMBLAZER]

Am i the only one who Almost never disconnects my battery? Most of the electrical i do requires testing, and you can't test dead circuits, so i've gotten pretty good at working hot. Its only 12 v, right? Most of my stuff involves trailer wiring, stereos, or alarms.

I used to...see my post from last year about melting one of Big Ugly's battery terminals...then again it is 24v still.
Then I popped one of the new fuses I put in while dicking with the stereo while the cables were still connected.

Plus, how do you listen to the stereo when you disconnect the battery?

Large house stereo in the garage. In fact I no longer even have a stereo in the house.