How to set up hands-free calling and fit the microphone
Open the Bluetooth app on the head unit, tap Search, select your phone and press Connect, then confirm the pairing on both. An external microphone is supplied and it plugs into the 3.5mm socket on Harness A. Where you mount it decides how you sound far more than any setting does.
What this gives you
Calls you can actually hold at highway speed in a 70 Series cab, which is a noisy place to try to have a conversation. The microphone is a separate item on a lead precisely so it can sit near your head rather than down in the dash behind a fan.
Before you start
- The supplied external microphone, which comes in the box.
- Bluetooth switched on at the phone, and the phone off its lock screen.
- A decision about where the mic is going before you route the lead. Moving it later means pulling trim again.
- The A-pillar trim or the steering column shroud accessible, since those are the two usual mounting spots.
Step by step
- Plug the microphone in properly
The mic lead ends in a 3.5mm jack and goes into its own socket on Harness A. Push it fully home. A jack that is half seated gives you a call the other person can barely hear, which reads as a faulty microphone.
- Mount it at about mouth height, pointing at the driver
The A-pillar or the steering column shroud both work. Aim the pickup at the driver rather than at the roof, and keep it clear of anything that rattles.
- Route the lead away from heat and tight bends
Keep it off hot air ducts and out of any sharp ninety degree kinks. A lead pinched behind trim is a fault that turns up months later.
- Keep it out of the direct airflow from a vent
Air blowing across the capsule sounds like a gale at the other end. Move it slightly inboard if it sits in the path of a vent, and never pack it in foam to fix that, because sealing the capsule makes it worse.
- Pair the phone
Open the Bluetooth app on the head unit, tap Search, make sure Bluetooth is on at the phone, pick your phone from the list and press Connect. Confirm the pairing on both the phone and the unit.
- Allow the microphone permission on the phone
On a call through CarPlay or Android Auto the phone can throw a microphone permission prompt. Take the phone off the lock screen and allow it. Tapping Only this time, or dismissing it, is how a working setup ends up silent on the next call.
- Test it on a real call, moving
Ring someone who will tell you the truth, get up to speed, and ask them how you sound with the fan on and off. A stationary test in a quiet driveway proves nothing about the cab at 100km/h.
If it does not work
- They cannot hear you at all: power the unit down, unplug and re-seat the mic jack, then power back up.
- You sound distant or echoey: the mic is too far away or pointing the wrong way. Move it before you change any setting.
- Wind or fan noise dominates: move the mic slightly inboard, out of the airflow.
- Music plays but calls have no sound at all: that is a Bluetooth profile problem rather than the microphone. Delete the pairing on both sides and pair again.
Worth knowing
The microphone is wired, not part of the head unit, so it is worth checking its plug and its position before assuming anything about the unit itself.
Related guides
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