These instructions apply to the Abarth 124 Spider (2016-2020).
For other models, please choose your vehicle here.
Disconnecting the 12 V battery on your Abarth 124 Spider (2016–2020) — the Mazda MX-5-based roadster with the Fiat 1.4 MultiAir turbo — is one of those jobs owners come to sooner or later. You might be fitting a new battery after the old one has tired, laying the car up for winter, chasing an electrical gremlin, or clearing the system before working near the airbags. Whatever the reason, it is a straightforward task, and as long as you take the terminals off and put them back in the right order the car relearns its settings cleanly and drives away as normal. The battery is in the engine compartment.
Where the 12 V Battery Is
The 12 V battery sits in the engine compartment, towards the rear of the bay near the bulkhead. Open the bonnet and look for the battery under its cover or clamp; there may be a plastic trim or a protective cap over the positive terminal that you lift or unclip first. Once you can see the two posts, identify them before you touch anything: the negative (−) terminal is the earth and usually wears a black cap or lead, while the positive (+) terminal is the live post, normally marked red and often hidden under an insulating cover. Knowing which is which up front stops you shorting a spanner across the two.
Before You Begin
- Make sure the ignition is fully off and the key is out of the car and away from it, so nothing wakes the electrics.
- Switch everything off — lights, climate, heated seats, wipers — and close the doors and the roof.
- Note down your radio security code if the car asks for one, along with your saved presets, so you can restore them afterwards.
- Give the car a couple of minutes after switching off for the modules to power down before you loosen a terminal.
- Have the right spanner to hand and wear gloves and eye protection; a car battery can deliver a lot of current if you slip.
Disconnecting Safely
- Switch everything off and remove the key from the car.
- Loosen and disconnect the negative (−) terminal first, then tuck the lead aside so it cannot spring back onto the post.
- Now loosen and disconnect the positive (+) terminal, and cover it or move it clear of the post.
- Working near airbags or seat-belt pretensioners? Wait 10 minutes after disconnecting before starting that work, so the reserve power in those circuits has fully bled away.
Reconnecting
Reconnecting is the reverse order: live post first, earth last.
- Refit the positive (+) terminal first and nip the clamp up snug.
- Refit the negative (−) terminal last and tighten it.
- Check both clamps are firm — a loose earth is the classic cause of odd faults afterwards — then refit any cover or cap you removed and wait about 5 minutes before starting the car so the modules can boot in order.
What You’ll Need to Reset Afterwards
Taking the battery off wipes a handful of short-term memories. On the 124 Spider that usually means:
- Clock and radio — re-enter the time and your presets, and the security code if the head unit prompts for one.
- Power windows — re-initialise the one-touch/auto function: hold the switch fully up until the glass stops, hold a moment, then hold fully down and back up so the motor relearns its limits.
- Steering-angle and stability — any ABS/traction light usually clears itself once you have driven a short distance with a few gentle turns.
- Service reminder — disconnecting the battery does not reset the service interval, so if a message was showing it will still be there.
If a Warning Light Stays On or the Car Feels Off
- Recheck that both clamps are tight and seated squarely on the posts.
- Take the car for a short, steady drive so the electronics can relearn and self-clear.
- Re-do the window one-touch initialisation if auto-up or auto-down has stopped working.
- Rule out a genuinely flat or worn-out battery — if it will not hold charge, no amount of resetting helps.
- A persistent light stores a code — look it up on autodtcs.com.
Frequently Asked Questions
Where is the battery on an Abarth 124 Spider?
In the engine compartment, towards the rear of the bay near the bulkhead. Open the bonnet and look under the cover or clamp; the positive terminal usually sits under an insulating cap.
Which terminal do I take off first?
The negative (−) terminal comes off first and goes back on last. On reconnection the positive (+) goes on first, then the negative. That order keeps a stray spanner from shorting the live post to the body.
What will I need to reset afterwards?
The clock and radio presets (plus any security code), the one-touch window function, and possibly a passing ABS or traction light that clears on a short drive. The service reminder is unaffected either way.
Do I need to recode or register a new battery?
A like-for-like 12 V battery of the correct size and rating normally just drops in with no coding needed. Only fit the type the car was designed for, and let it settle for a few minutes before starting.
Will disconnecting the battery clear fault codes or the service light?
It may clear some soft, self-resetting codes, but it is not a proper diagnostic reset and it does not turn off the service reminder. A genuine fault will simply log its code again once you drive.
Can I jump-start it instead of disconnecting?
If the aim is just to get a flat car going, a jump-start from a good battery or pack is fine and avoids losing your settings. Disconnect only when you actually need the battery isolated — for renewal, storage or work near the airbags.
If a warning light stays on after reconnecting, look up the code on autodtcs.com.
Independent guide — not affiliated with Abarth. Always follow your official service manual and safety precautions. Read our full disclaimer.