Toyota FJ Cruiser Forum banner

1 - 12 of 12 Posts

·
Registered
Joined
·
62 Posts
Discussion Starter #1
I thought what would happen if I bring my truck in to service--only to have the auto technician disconnect my batteries--and what would happen if he didn't realize it was connected to two batteries. Would he be okay just disconnecting the power from the negative main battery first and then the positive main battery (and leave the auxiliary alone)?

This is what I found while googling how to disconnect a dual battery system. It's from a Ford forum. Just wondering if this is correct.

Proper procedure for un-hooking dual batteries (both at the same time) is:
1) Disconnect the black, ground cable at Secondary Battery (LH).
2) Disconnect the black, ground cable at Primary Battery (RH).
3 Disconnect the red, positive cable at Primary Battery (RH) – then wrap insulation material around it.
4) Disconnect the red, positive cable at Secondary Battery (LH).
5) Remove old batteries and replace with new ones.
6) Reverse this procedure for hook up.

Proper procedure for un-hooking dual batteries (one at a time) is:
1) Disconnect the black, ground cable at Battery.
2) Disconnect the red, positive cable at Battery – then wrap insulation material around it.
4) Remove old battery and replace with new one/
5) Reverse this procedure for hook up.
 

·
Registered
Joined
·
3,283 Posts
I assume the RH and LH represents Right and Left Battery.... Looks like Ford has it right ALWAYS disconnect the battery ground connection First and when using multiple batteries disconnect those grounds before starting to work on the vehicle . I would tape the ground connector to avoid accidental connecting. The ground should always be the first off last on as far as connecting goes. ( unless you happen to have a rare positive ground vehicle)
 

·
Premium Member
Joined
·
1,277 Posts
One of the reasons I went with my manual setup. I just turn the switch to off. LOL
X2. I turn my switch off and remove the second battery from the equation. Then just pull cables on the main before doing work

Sent from AutoGuide.com App
 

·
Registered
Joined
·
62 Posts
Discussion Starter #5
X2. I turn my switch off and remove the second battery from the equation. Then just pull cables on the main before doing work

One of the reasons I went with my manual setup. I just turn the switch to off. LOL
By turning your "switch off", does that mean the same as "normal mode" (dual mode and emergency mode off) on a Dirty Parts kit (that's what I have)? I'm new to this dual battery system setup so I'm doing some research on here and you guys are always on top of it! :bigthumb:

Thanks!
 

·
Registered
Joined
·
62 Posts
Discussion Starter #6
I assume the RH and LH represents Right and Left Battery.... Looks like Ford has it right ALWAYS disconnect the battery ground connection First and when using multiple batteries disconnect those grounds before starting to work on the vehicle . I would tape the ground connector to avoid accidental connecting. The ground should always be the first off last on as far as connecting goes. ( unless you happen to have a rare positive ground vehicle)
Yes, I think that's what they mean by RH and LH although as we all know it's not always in those locations!
 

·
Premium Member
Joined
·
10,853 Posts
G'day,
I always turn my Blue Sea ACR off, first, thus isolating my batteries.
Then disconnect the earth / negative, on my primary battery and stick a block of timber between the cable and the battery terminal.
Tks Baz
 

·
Premium Member
Joined
·
13,321 Posts
I just worked on my stereo this last week. All I did was remove the ground from both the main battery and back-up and tested with voltmeter. No issues. I run the Dirty Parts Dual set up and made sure before turning off, the solenoid was in the "main battery only" position
 

·
Banned
Joined
·
9,090 Posts
X2. I turn my switch off and remove the second battery from the equation. Then just pull cables on the main before doing work



By turning your "switch off", does that mean the same as "normal mode" (dual mode and emergency mode off) on a Dirty Parts kit (that's what I have)? I'm new to this dual battery system setup so I'm doing some research on here and you guys are always on top of it! :bigthumb:

Thanks!
Nah in my setup the switch in the OFF position is no batteries connected. I have a 4 position switch OFF-1-BOTH-2.

A quick description is that both batteries are grounded to the chassis independently. Each battery POS is connected to it's individual input on the switch and then the vehicle and accessories connect to a common on the switch. Turning the switch OFF effectively disconnects both batteries POS.
 

·
Registered
Joined
·
62 Posts
Discussion Starter #10
I just worked on my stereo this last week. All I did was remove the ground from both the main battery and back-up and tested with voltmeter. No issues. I run the Dirty Parts Dual set up and made sure before turning off, the solenoid was in the "main battery only" position
Thanks for the reply! Would it be safe to flip the switch to "main battery only" position and then remove the NEG and then POS connections on my main battery (and leave the backup alone)? I'm asking this in case a mechanic or technician doesn't know what he's doing and disconnects it this way. I always disconnect both NEG terminals first, but I don't trust any mechanics.
 

·
Banned
Joined
·
9,090 Posts
^^^No. If youre going to do it, do it right and disconnect both negatives. The positives won't matter as long as the negatives are disconnected. If you want to be extra safe disconnect all 4 at the batteries terminals (negative of each first) but you need to do both negatives at a minimum to do it right.

No matter how unlikely, if you leave the second battery connected if in any way contact is made to it around the switch it will energize the system.
 

·
Registered
Joined
·
62 Posts
Discussion Starter #12
^^^No. If youre going to do it, do it right and disconnect both negatives. The positives won't matter as long as the negatives are disconnected. If you want to be extra safe disconnect all 4 at the batteries terminals (negative of each first) but you need to do both negatives at a minimum to do it right.

No matter how unlikely, if you leave the second battery connected if in any way contact is made to it around the switch it will energize the system.
Thanks! Yeah, I figured. I'm always worried about the mechs messing around with my stuff. I still have it under warranty. :cheers:
 
1 - 12 of 12 Posts
Top