Continue listening to the radio after turning your engine off

Since the CMU can take a while to come back to life after turning your car off, and then tapping the Start/Stop switch once for Accessory (ACC) mode, many of us miss the feature that many vehicles have where the audio will continue playing after stopping your engine, at least until you open your door or a programmed period of time has gone by.  Sergey (ssh16) has reported discovering that by holding the button on your Automatic shift lever while shutting down your 124 Spider with your left hand – kind of an awkward maneuver, you’ll  actually be in ACC mode rather than in OFF mode, allowing your radio to continue playing.

Apparently stopping the engine while in Neutral rather than Park will also keep your radio + USB ports on, and is probably the maneuver to remember when you wish to remain in the vehicle and continue listening to your radio/streaming audio, simply slipping it into Park after the engine has shutdown.  Again, you’ll  actually be in ACC mode rather than in OFF mode, and this gives you up to 25 minutes more time before the CMU turns itself off, but this can be extended by tapping the brake pedal once prior to that timeout, for another 25 minutes.

If you have a manual transmission, there seems to be no solution other than hitting the Start/Stop switch twice while in neutral and your foot off both the clutch and brake pedal.  If done quickly enough, you’ll end up in ACC mode with no interruption in radio play.


If you get in your vehicle, and want to simply listen to the radio:

  • without touching the clutch or brake pedal, tap the Start/Stop switch once for Accessory (ACC) mode.
  • in order to temporarily turn your ignition ON though (to operate the windows, wipers, etc.), you’ll need to tap it once more.
  • a third tap returns you to ignition OFF.

2 thoughts on “Continue listening to the radio after turning your engine off

  1. Wynn,

    Here’s a nice outlet that would be easy to install near the trunk lamp. I would not tap into the trunk light circuit because that wiring is not rated for the type of current that your 12 volt air pump (or other 10 – 15 amp device) would draw if plugged in.

    Instead, consider using my article on adding a radar detector as a guide and tap off of:

      Fuse # 6 (for switched 12 volts) OR
      Fuse # 9 or 10 (for always on 12 volts)

    and running a proper size wire from there to the trunk for your hot wire. The ground can be obtained at a bolt/nut in the proximity of your 12 volt outlet.


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