Crazy battery disconnect problem

[sed6]

Took my M925 to a car show today. I decided to unhook the batteries to prevent any problems like kids trying to start it or turning on my blower fan and running down the batteries. And therein I ran into trouble. I disconnected wire A and fully expected this to kill the truck. Nope everything still powers on. Okay, I then removed terminal B completely from the battery knowing this would kill everything. Nope! Finally I next removed terminal C and that killed everything. What the heck did I do wrong?

I'm new to MV's but not new to the planet. Everything I've ever worked on powers off when you remove the negative battery (cable A). Am I stoopid, do I need to read the TM, is my truck f*ed up?

Thanks all!

 

[rosco]

Do you have a couple of jumper wires in there? Is it back feeding through them?

 

[gimpyrobb]

Take the battery terminal off the top left batt and bottom left batt. Should only need a 1/2 wrench to do it.




Sounds like you took one + off and one - off. Since they are essentially two 24v batterys in parallel, you still had a + and a - connected. Thats why I said to take both - terminals off.

 

[foxtrk2]

ok from what I see in the pic the first wire you disconnected just took one battery out of line if yo uhad disconnected either of the lines comeing inthrough the hole in the side fo the battery box you would have killed the truck

 

[sed6]

Thing is, wire A is the negative wire that goes straight down thru the floor and wire B is the positive wire that goes straight down thru the floor. Are these not essentialy the same as the pos and neg wires under the hood of my car? There was a single jumper wire left, #569 IIRC, that feeds the 12v blower but how does a single wire power (with no corresponding 'return' wire), allow my dash volt gauge, the ABS light function check and my blower to all come on when I flipped the battery switch? I considered trying to turn her over but I knew that would melt something somewhere and let the smoke out of the wires. Of course this all bets the question, if I install a battery disconnect divide of some kind where the heck does it go?

 

[Coffey1]

If you have the slave port hook up. It will still ground truck and let everything power up but it won't start.
I put a cut out switch in the neg also and the truck will power up.
I put a cut in slave port still truck powers up it's

Andy put cut out on pos and totally kills truck.
Going to change mine just have to get some new cables made up.

 

[sed6]

Interesting. Thinking on it more, when I removed the neg cable I did tuck it under the battery hold down bracket to keep it outta the way. Perhaps it was touching the hold down and was still grounding. But still with the pos removed it shoulda been dead. I'm going to play with it again later today and report back.

 

[gimpyrobb]

You must not have understood what I posted.

You essentially have two 24 volt batterys.

You only disconnected one of the leads.

That is why you still had power.

Remove both negative terminals on the left most batterys.

 

[MtnSnow]

Yep Gimpy has it...Both battery strings need to be disconnected.

 

[Ray70]

Did you just pull posts A and B off the upper left and lower right batteries? Its hard to tell in the picture, but I think doing that would still leave the lower left and upper right batteries powering the truck.
I think that is also what Gimpy is saying.
If you want to be able to disconnect a single point to kill the truck you would have to modify your cables a little so that either the main + or - feeding the truck can be completely disconnected from the battery bank. Maybe you could rig up one of the battery disconnects with the screw knob on them somehow? Otherwise you'll have to remove several connections to kill the power completely.

 

[M35A2-AZ]

I have seen the slave port do something like that. Remove the neg. side of the slave port cable and use a ohm meter and test from the neg side of the port to ground on the truck and see if it is shorted. If it is then that may of been the problem.

 

[sed6]

I appreciate the tips. I haven't had time to re-investigate the problem (spent time fixing my winch instead). I'll report back when I get a little more time.

 

[papakb]

Here's a link to a manufacturer of battery quick disconnects. http://www.wirthco.com/battery-quick-disconnect-caps-p-59-l-en.html

Years ago I made the center link using these connectors so that all I had to do was to remove the battery box cover and unsnap it. This kills all power to the vehicle and stops the curious from screwing with it. Using these means no wrenching to connect and disconnect your batteries.

Kurt
KG6KMJ