DAB through 12V socket - stop/start issue

[alanshuff]

I've installed a Pure Highway 600 DAB adapter to my 2011 Toyota Auris, powered by the 12V power socket. The power socket is switched so is only powered when the ignition is on.

My issue is that when stop/start activates (specifically when the car restarts) it momentarily cuts power to the socket, which in turn reboots the DAB receiver and hence I have about 5 seconds of silence while it reboots.

Obviously I could just disable stop/start, but I would need to do that every time I got in the car.

I was considering piggybacking an 'always on' fuse - but I wasn't sure if that would still be momentarily cut on a restart.

Another option was putting a small powerbank between the receiver and the socket to hopefully continue powering it during a restart - but i'm not sure if that will actually work.

Advice on any of the above would be appreciated - thanks

[Stiggolas]

You don't want to put a power bank in there as they don't like to be continuously charged. Look up super capacitors. They will stop any momentary disconnects. I use one in my dash cam, it allows the unit to switch off and save when I cut the ignition.

[Spare tyre]

I’d just piggy back an always on circuit, the drain from the dab would be tiny

[AW10]

Curious if power is actually cut or if it's possibly a voltage drop at the socket that causes the receiver to drop out?

[alanshuff]

AW10 said:

Curious if power is actually cut or if it's possibly a voltage drop at the socket that causes the receiver to drop out?

I'm no electrician, but you're probably right - enough of a drop to reboot the receiver.

I tried piggybacking an 'always on' fuse, but had the same issue. It's weird - the actual FM radio in the car is fine when the car restarts, so it doesn't drop out, but this device does. And i have a similar unit in another car, connected the same way (i.e. the 12V socket) which is fine when using stop/start.

Seems to just be the way this car is. I've accepted i just need to remember to turn stop/start off when I get in, or make do without radio for a few seconds each time I pull away from the lights .

[anonymous-user]

Interesting.

1. You could have stop/start coded out.

2. Apparently there are suitable wires to piggyback. Some suggestions on the antenna wire (brown) on the back of the head unit. If you have a multimeter then check the voltage on that when start stop is active or make like a curious child and check other wires behind the head unit too. Only the unit not other wires.

3. Change head unit. Aftermarket replacement with built in DAB. Probably sound way better than your standard system but won’t look OEM and a potential thief magnet. Start from 100 for a single DIN unit. Might be less second hand.

4. Edited. The Super Cap is not a bad shout either but it might not give you enough. Perhaps 5-10 seconds from a £40 cap. You have to pay to play with caps and batteries e.g. split charging.

Edited by anonymous-user on Thursday 19th May 07:53

[ED209]

Could you power it from the diagnostic port? I use an adapter to power my dash cam from mine

[alanshuff]

I think if this was a good car which I intended keeping for a while i'd probably look at an aftermarket head unit with DAB and phone mirroring. I'm not knowledgable or technical enough to start dismantling the car and testing wires, especially as I can overcome the issue by switching off stop/start. It's annoying, but i'll adjust.

I've not tried the super cap or the diagnostic port - might look into these options during the summer.

As for the coding, I did get a Toyota Techstream cable/software from eBay and unfortunately that's not part of the customisations you can do - I did wonder whether there was some practical way round (i.e. disconnecting some switch) but i've not really got that far yet. Any deeper coding is not within my skill set i'm afraid

[Draxindustries1]

Introduce an additional battery like a car alarm 12v battery to your system rigged to your main 12v battery.
This will keep it charged through the alternators charging circuit.
Starting the car should then not have an effect on your dab radio.

[AW10]

That would probably require a diode or two to prevent the 2nd battery from trying to power parts of the car when the ignition is switched off. This is all getting a bit complicated…