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moisheh · 08-03-2018, 08:47 AM

Discussions about disconnecting your battery are all over Toad forums. When asked why the answer is usually: The mfr states to disconnect the negative cable. There are references to electric steering without any explanation. Once I am ready to tow my 2018 Sierra I will just install a disconnect and be good to go. Some owners do not want to go through that process. Last week I found a new in the package Family Motor Coach magazine from 2015 amongst my reading material. There is a discussion on disconnecting the battery cable and reference to a GM bulletin 13-00-89-007A. This bulletin applies to 2014 Chev PU's but some of it would be applicable to any vehicle with EPS ( Electric power steering) The bulletin clearly states that leaving power connected could damage the steering column. Being a doubting Thomas I could not understand how 12 volts would damage a steering column. Some Googling took me to a site that explained to techs how to diagnose problems with EPS. There are electronic components inside that column. Some of these components assist the system to return the wheel to center. I am just guessing but if that control is active it might be "fighting" the wheel. Regardless it seems we are disconnecting the battery to protect that steering assembly.

https://gm.oemdtc.com/7601/13-00-89-...ado-gmc-sierra

Ray,IN · 08-03-2018, 09:55 PM

You and that website are correct. The steering column is constantly powered, even with the key off, thus the admonition to remove the neg. battery cable. The system keep trying to match the wheel cut to the steering wheel position, which of course can never happen, so the system fights itself constantly when the wheels are not straight. A cable-operated battery disconnect in the neg battery cable IMO is the simplest solution and the easiest to control. It would also be a positive theft prevention device.

BCam · 08-25-2018, 12:55 PM

I know this isn't the case with your toad but some vehicles need to have the battery connected to be towed, so one should be careful to follow what's appropriate for their specific toad.

If battery power is required, a charge line from the RV should be installed to prevent the toad battery from dying,

Sbrownstein · 08-25-2018, 01:21 PM

Obviously it depends on the design. My Enclave says to remove 3 fuses from two different fuse blocks. I installed a charge line and leave everything powered. On my TOAD, from what I can tell it is all about killing the battery with the key in the ACC or ON position.

I do, however, accumulate mileage when towing.

cvbdsl · 08-25-2018, 04:00 PM

Just a follow up question on this - mine also says disconnect the negative side.
I know that normally for safety you disconnect the negative before the positive before removing the battery. Is this the reason they say disconnect the negative?

Most battery disconnect solenoids I have seen are connected to the positive terminal. In my case the negative disconnect is so far back I can just barely reach it (it is actually so far back it is under the dash). I would like to add a remote disconnect but they all seem to connect to the positive terminal, which in my case is much easier to reach.

So would a positive battery disconnect make a difference? I can't see that it would (no current equals no current either way) but I've been wrong at least once or twice before according to my DW

.

Thanks

Chris

Skiddy · 08-25-2018, 04:10 PM

I have always used the positive side to the disconnect switch. my reasoning is that even if the negative is unhooked from the battery it could still find a ground elsewhere. just what my lil brain thinks

barmcd · 08-27-2018, 01:11 PM

I have to keep my Ford powered, I assume because it has an electronic transfer case.

ScoobyDoo · 08-27-2018, 04:00 PM

I don't know anything about the whys of unhooking a battery. I do know that if removing the cable, you want to unhook all the Negs before you mess with the POS. If, while unhooking the Neg, and your wrench contacts the post and most anything in the area, nothing happens. But in Neg is connected and you get careless working on Pos, you can have lightning in your hand, fire in your face and acid raining all over. In my tool box I have some short pieces of rubber hose to slip on the post so I'm sure the stiffness of cable can not let it make contact.
I see no reason why you could not unhook the ground, put a disconnect switch on Pos side, then reconnect ground.

BCam · 08-27-2018, 11:35 PM

Quote:

Originally Posted by Skiddy

I have always used the positive side to the disconnect switch. my reasoning is that even if the negative is unhooked from the battery it could still find a ground elsewhere. just what my lil brain thinks

There's no way it can "find a ground elsewhere". It's not like your house wiring where the actual "ground" is a ground. If the negative post is isolated from the frame of the car there's no way for the circuit to be completed between the positive and negative posts of the battery. In terms of current flow, it doesn't matter which post is disconnected.

From what I've read on various automotive forums, although there is some debate, it's preferable to mount a disconnect switch, particularly a knife blade type switch on negative post. Apparently this is because such a switch adds a lot of bare metal to around the post which can be susceptible to being accidentally shorted to the frame or other metal parts by a wrench or other tool, causing a short circuit. The negative post is safer since accidentally shorting it to the frame or other metal part will not cause a short circuit. I also read that some of the racing organizations require that disconnect switches be on the negative post.

bharrisv65 · 08-31-2018, 05:09 AM

Quote:

Originally Posted by Skiddy

I have always used the positive side to the disconnect switch. my reasoning is that even if the negative is unhooked from the battery it could still find a ground elsewhere. just what my lil brain thinks

Skiddy, no disrespect meant but just wanted to make sure to clarify, if you disconnect the ground terminal, there's no way for it to "find a ground elsewhere", that will only happen if that terminal touches the negative battery post again, period. Envision this, the negative terminal (from THAT battery) goes from the battery to a "ground" somewhere on the frame of the vehicle so once it's unhooked, there can be no grounding of the vehicle to THAT battery unless the unhooked terminal or something else on the frame touches that battery's negative terminal. Even if grounded to the towing vehicle's battery doesn't matter, it will have to ground to the battery in the TOWED vehicle. Clear as mud I hope, LOL.

Dutch Star Don · 09-05-2018, 10:48 PM

"moisheh"......glad you posted this. Many feel that if they run a charge line or turn the key OFF, versus "ACC" that they have defeated the need to disconnect the battery. As you found out, the electric steering never shuts down, (when the battery is connected) and tries to center itself. Over time, the steering can be damaged.

I use the Roadmaster battery disconnect on the positive (+) side. It doesn't matter which cable you disconnect. The reason GM says negative cable is so that someone doesn't do something stupid with the positive cable. One of the only caveats to the Roadmaster disconnect, is that it can't be used with diesel engines (like the Canyon and Colorado trucks) as the draw too many amps when starting.