[r100gspd]

My stereo - Pioneer DEH 4400BT is normally fine - on all time with key out if required, but when I turn key to start it goes off while cranking and then comes back on again.
It is not normally an issue except when playing music through my walkman NWZ A17 via bluetooth which makes it lose where it was, and I have to then reconnect which is a PITA
Not sure if the supply to the stereo is interrupted whilst cranking, or whether starter causes voltage drop which causes stereo to go off momentarily. It does not lose radio presets.
Any ideas to remedy this please?

 

[Rich_wookey]

I thought that was normal behaviour

 

[spankdanny]

Yes it's designed to do that to give max amps to the starter and fuel/ignition systems. I think it is done by the connections on the ignition switch. You would have to find a permanent live maybe off the switch itself.

 

[r100gspd]

Yes it's designed to do that to give max amps to the starter and fuel/ignition systems. I think it is done by the connections on the ignition switch. You would have to find a permanent live maybe off the switch itself.

In that case will probably take a 5A inline fused supply off the existing fused supply from battery+ to the demister relay in boot, under rear seat and centre console using 2.5mm2 flex to minimise voltage drop.
Can't see this affecting fuel/ignition

I thought that was normal behaviour

Maybe, but still a PITA :-(

 

[MalcQV]

Can't remember a car that has not done that, unless maybe wired directly to the battery. Probably had an old car wired like that once, about 5056 years ago :lol:

 

[pkr]

The way to prevent that happening would be to have a small 12 volt battery pack wired in such a way that the additional battery will supply the radio when the voltage drops from the main battery. In order to achieve that, you'd need to prevent the additional battery pack from trying to help start the car. A diode* would do that by allowing the car to charge the additional battery but not discharge it. Think of the diode as being a one way valve for electricity. Another way may be to wire a relay coil in with the 'start' position of the ignition key and the relay isolates the additional battery from the car.

This isn't particularly difficult although I've never looked to see if there's a commercially available solution. Caravanners do split charging as a matter of course with the batteries fitted to the caravan.

You could probably use a small 12v battery typically used as backup batteries in domestic alarms, UPSs etc. e.g. 12V Sealed Lead Acid Battery 1.3Ah 1 Pack | Maplin

* A diode may not be the ideal solution however as it will result in a voltage drop to the additional battery pack which may cause an issue with charging it.

 

[alexGS]

It's a really handy feature to hear the engine start, instead of the radio. It's also nice that all devices, including the headlights, are spared the voltage fluctuations that would otherwise be caused by the engine cranking.

I start the engine before turning my phone Bluetooth on, anyway. On an iPhone, you just swipe from the bottom of the screen and tap the Bluetooth icon.

-Alex

 

[Dansolo]

Its never been an issue for me , turn key , wait for the dash engine lights to go out , start car then turn on stereo .

No dramas .

Like Alex says its nice to hear the engine turn over rather than Royal Blood blaring out the wireless.

 

[r100gspd]

Anyway,seats out,threaded wire through console and now have hidden wire from battery to near stereo so I can join up next. Whilst some may like to start up and then turn on stereo, I like to browse albums before starting up and then fire up and go. It is not easy sorting through 192GB of mp3s when on the run. Hopefully the live feed will work when I connect it up.

 

[alexGS]

For what it's worth, I plug my phone in (to USB of the Alpine headunit) instead of using Bluetooth - better sound quality and my phone gets charged as a bonus. It sits on the ashtray lid quite happily.

-Alex

 

[Markalfa15]

Like previous poster has said its to give max amps to starter.Seen it on older cars maybe the lights are the same? Not really a problem.Whats more annoying is the way the stereo is wired permanent live .It stays on when u turn ignition off .Most they go off with ignition .Its an italian querk i suppose

 

[r100gspd]

The separate feed from battery didn't work as when cranking, voltage dropped to 9v and stereo apparently needs 9.8-15.4v. Usual feeds which are permanent live also dropped to 9v but didn't turn off
So PKR's solution looks like next step.
Now to reset airbag light as I disconnected front airbag switch when removing console side carpet:furious: