Bluetooth Handsfree Stereo in S1 Elise

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Bluetooth Hands Free - No Sound

With some Bluetooth based hands free stereo head units you may find you get no sound through your speakers, in particular Sony head units. This is due to the head unit expecting front speakers for producing the sound from your hands free call. The S1 Elise only has rear speakers as standard and the ISO socket for the stereo head unit is wired for rear speakers.

The simple solution is to swap the front and rear speaker pins over so the head unit now outputs from the front speakers using the speakers behind the seats. On the Sony set up you are normally supplied with a patch cable that converts the Sony socket to the standard twin ISO plugs in the Elise dashboard. For this solution I have simply changed the pins over on the patch cable as this can be done easily on the bench rather than with the wire hanging from the dash. There is no re-wiring or soldering required. If your head unit plugs straight into the Elise ISO plugs then you will need to change the pins on the ISO plugs.

First (if patch cable/Sony), take the patch cable and identify the ISO end, this will be the end of the cable with two sockets with flat pins inside. Now identify which is the power socket and which is the speaker socket, the speaker socket is likely to be the one with the full set of wires connected (8 wires), but also if you look at the one side of the socket you have a locating slot on the side, the power socket has an off-set slot and the speaker socket has the central locating slot. For further help take a look at the ISO standard on Wikipedia;

You can see in the photo on this page that a plug is shown rather than the socket you are adjusting, the side of each plug has bits sticking out, this is for the locating slot, the lower brown one with the central locating slot is the speaker plug/socket, this is the one you want. Before starting it may be worth noting which colour wires (some are the same colour but with a black line) go in which location.

To swap the front and rear speakers over you need to take the middle two on the top row and swap them over with the outer top two, and the bottom middle two and swap them outwards again. Have a look at the 'Speaker connector (Plug B)' table in the Wiki link above, 'right rear (+)' needs to be swapped with 'right front (+)' and 'left front (+)' with 'left rear (+)'. Also 'right rear (-)' with 'right front (-)' and finally 'left front (-)' with 'left rear (-).

Swapping will require a tiny longish flat screw driver. Insert the screw driver down the shaft of the pin you want to remove (down the socket end rather than the wire end of the socket) and then when you reach the end push the screw driver down to the pin, this will push the pin-lock down so it can be released and pulled out by the wire. It may take a couple of goes before you get it removed successfully, take a look down the shaft of the pin with an inspection lamp to see what you are pushing. It's also best not to pull the wire until the lock is pushed down, in fact pushing the wire into the socket can help sometimes.

Do the pins in pairs so there is no confusion in replacing them. When you remove a pin you may need to reset the pin lock as it can go flat with the pin, just push the tab/lock back up from the pin carefully without bending the pin. Put it into the new slot until is clicks and locks in place. Once 'all' pins are swapped over, plug in and test before completely pushing the head unit back in.

Just remember that if for any reason you using the Front-Rear Fader (not much point with just rear speakers, the speakers will now be on the Front Fader. If you ever install front speakers then these will now be rear so you will probably want to change them back.