Short answer: "it will not connect" and "it keeps dropping" are two different faults, and the fix that people reach for first — delete the device and pair again — only treats the first one. Working out which of the two you have takes about thirty seconds and saves you from repeating a fix that was never going to work.
Two faults, two fixes
| What you see | What usually causes it | What fixes it |
|---|---|---|
| Never connects; fails immediately; the device does not appear at all | A stale or mismatched pairing record on one side | Delete the device on both ends, then pair again |
| Connects fine, then drops mid-use; drops in one place only; drops after minutes of idle | Radio interference, or a power-saving policy on one of the devices | Change the environment or the power settings — re-pairing will not help |
The distinction matters because the second case is far more common than people assume, and the standard advice ("forget the device and start over") does absolutely nothing for it. You delete the pairing, you pair again successfully, and it drops again an hour later — which is the point at which people conclude the hardware is broken. It usually is not.
When re-pairing is the right answer
Pairing is not a one-time event; it is a shared key stored on both devices. If either side loses it, updates it, or ends up with a stale copy — common after an OS update, a restore from backup, or having paired the device with something else in between — the two devices stop agreeing, and every connection attempt fails at the handshake.
That failure looks like this: the device appears in the list, you tap it, and nothing happens, or it appears to connect and drops within seconds, every single time with no variation.
The fix has one detail people skip: delete the pairing on both ends. Clearing it only on the phone leaves the accessory still believing it holds a valid key, so the re-pair can fail or produce a half-working connection. Do it on the phone first (Settings → Bluetooth → ⓘ → Forget This Device), then do the equivalent on the other device — with most headphones that is a long-press on the pairing button until the light flashes differently.
If, after a clean re-pair, you get a genuinely stable connection, the record was the problem. If it drops again within the hour, the record was never the problem and you should stop touching it.
When it keeps dropping: interference
Bluetooth runs in the 2.4GHz band, which it shares with Wi-Fi, and that band is crowded. The practical consequence: drops that happen in one location but not another, or that started when you plugged something in, are almost always interference rather than a fault.
The usual suspects, in rough order of how often they turn out to be it:
- A USB 3 device sitting near the phone or the accessory. USB 3 ports and cables are known to radiate in the 2.4GHz range. Moving the cable or the drive a foot away has fixed more "broken Bluetooth" cases than any setting.
- Wi-Fi congestion. A router on a crowded channel raises the noise floor for everything sharing the band. If the drops happen near one particular router, that is a strong signal.
- Physical obstruction. The body is largely water, and water absorbs 2.4GHz readily. A phone in a pocket on the opposite side of your body from the earbuds is a genuinely worse link than the same phone in a hand.
- Too many devices. An office or a train carriage full of active Bluetooth is a hostile environment for any single link.
None of these have a settings-page fix. They have a physical fix: move things apart, change the router channel, use the wired option when it exists.
When it keeps dropping: power-saving
The other common cause is that one end decided to sleep. Accessories drop their link to save their own battery after a period of no audio — which is expected and correct, but reads as "it disconnected again."
On the phone side, Low Power Mode reduces background radio activity, and a device that reconnects constantly in normal use can behave differently while it is on. If the drops correlate with battery level or with Low Power Mode being enabled, that is the explanation, and it is not a fault.
The distinguishing feature is timing: interference-driven drops are random and cluster by place, while power-saving drops are regular and cluster by idle time — nothing happens for N minutes, then it goes.
CarPlay: wired and wireless are different problems
This is worth separating, because they fail for unrelated reasons and people often test one while diagnosing the other.
Wired CarPlay is a data connection over the cable. The failure mode that catches people: many USB cables are charging-only — they carry power but not data. A cable that charges the phone happily can be incapable of CarPlay, which is why "try another cable" is the correct first move and why a cable that works for charging proves nothing. After the cable, the next most common cause is lint or debris in the phone's port, which breaks the data pins before it breaks the power pins.
Wireless CarPlay uses Bluetooth only to discover and hand off, then runs the session over a direct Wi-Fi link between the phone and the car. Two consequences follow. First, turning Wi-Fi off disables wireless CarPlay entirely, no matter how good the Bluetooth connection is. Second, wireless CarPlay can fail for reasons that have nothing to do with Bluetooth — a car head unit that has run out of Wi-Fi slots, or a phone that is simultaneously attached to a different Wi-Fi network and refusing to hand over.
A useful test when wireless fails but wired works: forget the car on the phone, forget the phone in the car's settings menu, then reconnect with the ignition on and the car parked. Wireless CarPlay pairing is fussier than Bluetooth pairing because it has to establish both links, and a half-established state on either one produces exactly the "it connects then immediately drops" symptom.