I'm about to install dual batteries in my 1997 80 series and I was wondering if someone could look over my wiring diagrams for errors. Other than wiring a car stereo, I haven't done a lot of electrical work. Thanks!
Wiring Diagram - How badly did I screw this up?
- Thread starter Aeneiad
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well, I can't tell what all those electronics bits are but presumably one of those batteries has the negative terminal to ground as well? Otherwise there may be an issue. 
Are you relying on the body for future accessories to get to ground?
Are you relying on the body for future accessories to get to ground?
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Yeah, I definitely forgot to add that. The start battery, (on the right) has the factory ground.
There are 3 16GA wires on the ACR. Ground & Start Isolation need to be hooked up.
Fuse all your positive leads as close to the battery as possible. I’d go with AMG or ANL 150a fuse for each lead going from battery to ACR. Circuit breaker for the fuse block in the quarter panel would also need to be close to the battery, or fuse that aux positive at the battery then in addition add the CB at the fuse block for easy cutting of power.
Grounds are important. I grounded my aux batt to match the start battery. One 8awg body ground at the PS inner fender, one 2awg ground to the block under the exhaust manifold. i Tend to ground accessories at the battery when possible or run a large cable to a common negative block and ground accessories there.
Grounds are important. I grounded my aux batt to match the start battery. One 8awg body ground at the PS inner fender, one 2awg ground to the block under the exhaust manifold. i Tend to ground accessories at the battery when possible or run a large cable to a common negative block and ground accessories there.
I utilized similar components. But didn’t go the dual battery route. I ran 4ga marine from the starting battery all the way to the rear fuse block. Someday I may go dual battery, but for the time being, it works good.
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I believe only the reference "black" wire or ground needs to be hooked up for it to function.
I'm about to install dual batteries in my 1997 80 series and I was wondering if someone could look over my wiring diagrams for errors. Other than wiring a car stereo, I haven't done a lot of electrical work. Thanks!
Unless the batteries are next to each other, I assume they are on separate sides of the engine bay. You need to add a fuses.
That’s what I thought. Batteries never auto-combined until red wire was hooked up to a switched positive.
For ML-ACR series the red wire is the override. The ACR will work with just the black wire hooked up. It might be mis-wired or malfunctioning if it wasn’t working for you with just the black wire. Make sure that your reference ground was not isolated from the “engine” ground.
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The only thing that could be optimized there is the ground, and only for the purpose of using less wire. The start battery grounds to the engine block, and as @Shoredreamer says, there is a nice spot to do the same for the second battery.
Had just put together a similar diagram for our components: Basic Dual Battery Diagram
Had just put together a similar diagram for our components: Basic Dual Battery Diagram
Negative to negative on the battery? Where is the ground wire?
Ground is via the main battery grounds.
I've mine wired like that for years - should be functionally identical vs a ground to the block on the Aux battery right ?
Asking to ensure I'm not driving a fireball in waiting
I've mine wired like that for years - should be functionally identical vs a ground to the block on the Aux battery right ?
Asking to ensure I'm not driving a fireball in waiting
