New head unit keeps rebooting in car but is fine on a bench PSU - car battery issue?

Hi,

Finally I have all the bits & pieces together to fit the new Android based head unit in our 2010 Picasso. Full gory details & photos as soon as this project ever ends!

I test-fitted the head unit at the weekend and whilst the unit fired up ok, the DAB scan went well, FM & DAB sounded fine..... after around five minutes the unit turned itself off. Then when attempting to boot it up again it gets 20% of the way in and again, switches off.

Cautious that the car might have been going into Economy Mode [and not displaying the fact on the car's display for some reason] I fired up the engine to make sure I wasn't draining the battery without at least having the alternator charge it at the same time. Same problem, the unit boots 20% and switches off.

This isn't the most expensive unit China has to offer but it's at least a known brand within its sector ("Xtrons") so I gave it the benefit of the doubt and hooked it up to a bench PSU by connecting +12v to the ISO connector's yellow & red wires and 12v GND to the ISO's black lead. The head unit has been running perfectly for hours. I can power-cycle it, download apps over WiFi, playback on Spotify....

I haven't yet had a change to hook up a voltmeter to the car's battery - but does this sound like a battery issue? In a former life I user to repair iPhones and the symptoms feel similar; dead or close-to-dead battery just doesn't have enough grunt to boot the device.

Having said all this, when the head unit is connected to the bench PSU it only shows a current usage of 700mA @ 12V so it's not exactly power-hungry. Also the Picasso (HDi) fires up perfectly on first crank.

Any suggestions would be most welcome.

Thanks,

Steve

Pointless photo attached!

Probably not a battery issue but check your alternator voltage output at various RPM and loads.

Thanks. Would that be by taking measurements at the battery terminals [with the engine running] , to check the alternator voltage?

Also - as this problem is reproducible with or without the engine running, does that still point to the alternator?

Cheers,

Steve

Yes, to check the alternator measure the voltage at the battery terminals after checking they are tight and have no corrosion to make a good contact to the battery and the clamps.

You test the alternator with the engine running.

With the engine off you will get some information about the battery.

As you say, if it happens with engine off, then its not the alternator. But if you have battery problems, check the alternator.

What happens if you connect the yellow and red leads on the Xtrons together and connect both to the permanent 12 volts on the car?

Also, what option did you go for to get a switched 12v supply from the car?

Hi,

Here's the latest:

• The Picasso's battery seems OK, showing 13V on an AVO with the engine off, voltage drops briefly when starting the engine as expected but then immediately returns to 13.5V or thereabouts once the engine fires.
• I've tested the voltage at the ISO harness in the car and that too shows the same 13V as connecting directly to the battery, across both the ISO connector's red & yellow leads .
• For now I don't have the DAB adapter or the [powered] FM / DAB antenna splitter hooked up, I'm trying to keep it as simple as possible until this "rebooting issue" is resolved. So my setup is "simply" the Xtrons head unit plugged into the DynamicSounds adapter (see below).

1) To hookup the Xtrons to the Picasso I'm using this kit from DynamicSounds: https://goo.gl/fVwgfi . Which apparently should enable the Picasso's steering-wheel-controls as well as adapting the Xtrons ISO socket to the Picasso's.... whatever it's called; the "main audio & power connector". As per the "CTMULTILEAD.2" instructions which came with the DynamicSounds kit (a Connects2 product?) I've wired the Key1, Key2 and GND leads to the corresponding wires on the Xtrons

2) In the car I haven't tried linking the red & yellow wires at the Xtrons end (which worked fine on the bench PSU) as I read somewhere that this may damage the adapter shown above or send voltage to the CANbus ?

3) Something else I haven't been able to do yet is programme the steering wheel controls. If I understand it correctly, this requires using the "Steering Wheel" app that's installed on the Xtrons... which of course means the thing needs to be booted up to use it!

Cheers,

Steve

steveharman wrote: ↑Mon Jun 04, 2018 1:43 pm 2) In the car I haven't tried linking the red & yellow wires at the Xtrons end (which worked fine on the bench PSU) as I read somewhere that this may damage the adapter shown above or send voltage to the CANbus?

I was thinking to connect red and yellow wires from the radio to a permanent 12 volts from the car harness/adaptor. I agree, it isn't wise to join leads from the adaptor together but on the radio side you'd just be doing the same as running the unit from your bench power supply.

If the radio works OK with red and yellow wires connected to the vehicles 12 volt supply then your problem must be with the adaptor?

I'm coming around to that way of thinking too. I'll ping it back to the supplier and see what they say.

Thanks,

Steve

UPDATE: Situation resolved.

Thanks to all the knowledge I gained from folks on here, I was able to accurately describe the problem and what steps I'd tried to the extremely helpful tech support and Dynamic Sounds who supplied the adapter. The first thing the guy said was:

"Check the Xtrons unit's ignition live and permanent live in their plug. It is probably the wrong way round compared to our adapter"

And what do we notice in the following image?
• Thin red in one end > thicker yellow out the other
• Thick yellow in one end > thinner red out the other

Apparently one of these delivers far more current than the other - if I had to guess I'd say the yellow as it was thicker. Thus once the head unit was up to speed, CPU doing lots of things like music playback. radio etc. it would be drawing more than the available current (with the original wiring) and shut itself down. Having investigated how to remove pins from an ISO socket using paperclips (https://www.youtube.com/watch?v=ddZpGBTsnlI - it's not in English, but the point is pretty clear) I swapped over the red & yellow lead and all is well.

Even managed to programme the Picasso's steering wheel controls which couldn't have been easier using the pre-installed app; you get a grid of functions, tap the one you're interested in (say, "Volume +") and press whatever button you like on the car's steering wheel controls. I went for "Vol+" as I'm a bit traditional like that.

Thanks again for all the help received here and I _will_ be doing a post about how I got on, with photos, as soon as I'm done.

Cheers,

Steve

steveharman wrote: ↑Mon Jun 04, 2018 5:12 pm UPDATE: Situation resolved.

I swapped over the red & yellow lead and all is well.

Even managed to programme the Picasso's steering wheel controls which couldn't have been easier using the pre-installed app; you get a grid of functions, tap the one you're interested in (say, "Volume +") and press whatever button you like on the car's steering wheel controls. I went for "Vol+" as I'm a bit traditional like that.

Thanks again for all the help received here and I _will_ be doing a post about how I got on, with photos, as soon as I'm done.

Cheers,

Steve

Thanks for the update and the solution