Disconnecting vehicle battery

Faults and Technical chat for the Mazda CX-3
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mum@mazda
Posts: 126
Joined: Mon Aug 31, 2015 8:55 pm

Post by mum@mazda »

Are there any special precautions before disconnecting the battery. I have jyst bought the towbar electrics harness and this is the 1st thing to do, i dont think there are any radio codes or things like that, but thought i would ask you guys.

Cheers
CX-3, Sport Nav, Petrol, Soul Red Metallic, Half Stone Leather Aug 2015

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anchorman
Posts: 1071
Joined: Tue Jul 07, 2015 4:23 pm

Post by anchorman »

I had mine disconnected with no ill effect but make sure the windows (including sunroof if fitted) are all shut first. I’ve attached a bulletin which describes more how to take the terminal off in one swift move to save any arcing damaging the ECUs.
CX-5 Sportnav diesel auto. AWD
TAX
Posts: 66
Joined: Thu Sep 07, 2017 3:02 pm

Post by TAX »

Whilst I am away, my CX3 petrol auto will be garaged for 4 months over the winter and I will disconnect the battery.

Do I need to disconnect both terminals, or just the negative terminal.

When re-connecting, are there any codes etc. to input, or should everything, including the keyless entry and central locking, just resume as normal as in Anchormans experience above.


Are there any other precautions necessary in order to guarantee a trouble free start up.

Thanks for any advice or hints.
SEPT 2017
CX3GT AUTO PETROL. CERAMIC METALLIC. 39 MPG
YORKSHIRE.
TAX
Posts: 66
Joined: Thu Sep 07, 2017 3:02 pm

Post by TAX »

I disconnected the negative terminal, (handbrake off, windows closed, drivers door locked with the key after manually locking the other three doors before disconnecting) last November and garaged the car over the winter.

Last week, I reconnected the battery and am pleased to report that the car started first time, there were no warning lights showing and the radio had retained all the programmed stations. The tyres all retained the pressures exactly as I had left them 5 months ago.
SEPT 2017
CX3GT AUTO PETROL. CERAMIC METALLIC. 39 MPG
YORKSHIRE.
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jtonline
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Post by jtonline »

Good news. Thanks for the update.
Julian.
Sept. 2015 CX-3 Sport Nav, Dynamic Blue Mica, 1.5 Diesel, AWD, Automatic
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PurbeckCX3
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Joined: Fri Oct 21, 2016 4:08 pm
Location: Dorset and Marbella

Post by PurbeckCX3 »

Did you then leave the bonnet open so you can get access to reconnect the battery or can you unlock with the key even though the battery is disconnected?
Thanks Rob
TAX
Posts: 66
Joined: Thu Sep 07, 2017 3:02 pm

Post by TAX »

I locked the rear doors and passenger door using the lock buttons before disconnecting the battery.

After disconnecting the battery, I locked the drivers door manually using the key that lives inside the "key fob" and fully closed the bonnet.

The key unlocked the drivers door even though the battery was disconnected.

Normally I would remove both terminals when disconnecting a battery, but the positive terminal seems to be connected to some kind of electronic control box (maybe part of the i-start system??) and it looked too intimidating to mess with.

I left the handbrake off, and I had placed a few thick carpet squares under each tyre to prevent the tyres from developing flat spots whilst being left for so long. It seemed to have worked.
SEPT 2017
CX3GT AUTO PETROL. CERAMIC METALLIC. 39 MPG
YORKSHIRE.
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