Stereo switching off whn not running, intermittent

[Troopy]

Hi all, got a bit of a puzzler.

When engine is not turning over but ignition on, my stereo keeps switching itself on and off if the volume was left high when I last stopped the bus.

Fine when running.

It currently runs four 6x9 passive speakers.

Battery and alternator are fine and belts recently replaced so can only think it is an electrickery issue, maybe overload on something.

Anyone got any ideas?

[adie89]

Check your load reduction relay, it supplies the stereo when the ignition is on but cuts it out when the engine cranks.
You could also be overloading your head unit with the draw at max volume. You need to check the head unit output in the book or online 4x50w is generally for a good quality unit. Your 6x9 probably can pull a lot more than that(look at the RMS value). Which will work but will burn out the head unit early if it’s working too hard too often. Get an amp?

[tobydog]

Voltage drop causing amp to turn off?
Turn the volume down before stopping the bus....

[bigbadbob76]

Voltage drop causing amp to turn off?

Sounds right to me. Unless you've upgraded the stereo supply wiring and/or are using a separate amp then the thin VW wiring will be dropping several volts when the speakers are being driven hard.
OK when running because the alternator/voltage regulator are keeping up with demand.
I'd use a separate amp personally and supply it with good quality thick cable.

[adie89]

Voltage drop causing amp to turn off?

Sounds right to me. Unless you've upgraded the stereo supply wiring and/or are using a separate amp then the thin VW wiring will be dropping several volts when the speakers are being driven hard.
OK when running because the alternator/voltage regulator are keeping up with demand.
I'd use a separate amp personally and supply it with good quality thick cable.

Second that, but as CovKid always says, upgrade your alternator to battery cable and battery to fuse box cable