General Fiat Doblo, Car Radio not wroking with ignition off ?

[OldGeek]

If this sounds daft, be gentle with me....
My enthusiasm for cars has gradually diminished over the years, so I don't keep up with new developments like I used to.

My Doblo doesn't have an "accessory" position on the ignition switch, so it looks as though I have to choose between wiring it to a permanent pos feed, (where I might forget and leave it on), and a switched pos feed, where I can only use it with the ignition on.

I haven't quite worked out how the existing bluespot CD radio is connected, as sometimes I can use it with the engine off, and sometimes not, so I'm not sure if there is a clever setting in there somewhere.

I've just temporarilly plugged in an Android head unit (satnav etc), via the standard DIN connector and that only appears to work with the ignition on (and therefore the engine running). So although that DIN wiring ahs two live feeds, one switched and one permanent, it is only being enabled when the engine is running.

Is there a way to "have my cake and eat it too" ? eg be able to run it with the engine off but needing the key in, so I can't forget it and leave it on when I leave the car ? That was available with every other make of car that I've had in the past.

 

[OldGeek]

Since starting this thread Yesterday, I've found some instances where owners have questioned Fiat's lack of an "ACC" position on their ignition switches. Owners of other Fiat models have expressed disappointment and surprise at having to have their engine running to listen to the radio when parked. I'm still trying to find out whether there is possibly a factory setting in my after market Android head unit (an xtrons), to enable it to be used while the main pos supply is off. As most car radios have two live feeds, one via the ignition and one permanent live (to keep station settings in memory etc.), I believe it may be possible for an Android unit to give me the best of both worlds, ie switch off automatically when the engine is stopped, and yet still detect the on switch being pressed and power itself via the "always on" feed.

Failing that, I guess I'll have to swap over the live and switched pos feeds (red and yellow) in the DIN connector, as the only way to be able to use it without the engine running.

radio din connector swap red and yellow - Google Search

 

[OldGeek]

Another update fro me.
The plot thickens........
I'm now discovering "Canbus adapter" harnesses, for specific makes and models, that link aftermarket radios into the Doblo's wiring, including connections to the Canbus. The cheapest so far is around £40, so I'm trying to find out what the actual connections are and if there are any intermediate electronics within them.

 

[OldGeek]

The (excellent) Doblo workshop manual downloadable from this forum throws more light on the subject. (I should have searched it first).
The pages about the factory fitted radios explains that it somehow links into the car's canbus to be able to auto switch off when the key is withdrawn, and also allows off-engine usage in 20 minute intervals. The accompanying wiring diagrams show connections to the car's canbus "A" and "B" wires within the radio's standard DIN connector. So presumably the special Doblo canbus adapter somehow connects this to aftermarket radios via some unknown componentry.

 

[OldGeek]

After much research and investigation, I am now an "expert" in aftermarket radio replacement in series 1 Doblos, (and possibly other Fiat canbus vehicles with no "accessory" postition on the ignition keyswitch.

"Universal" Android head units usually have three wires for their power supply. A constant negative ground, a constant battery 12v postive, and an "accessory" switched 12v positive.

The 2007 Doblo is equipped with a "Canbus" system, which talks to the original factory fitted bluespot radio to enable it to work when the ignition is on, and turns it off when the keys are taken out.

So I had two main options to get the Android head unit working, either pay about £40 for a Canbus "interface" to daisy-chain in the radio's DIN loom, or connect the head unit's "accessory" switched positive lead to its constant positive lead. I decided on the latter option, not only because it was cheaper, but it would give me full use of the head unit whether the engine was running or not.

The downside was that by default, when you turn an Android head unit off, it goes into standby mode instead of switching right off, so it would drain even a 60ah battery within a few days. Further research into that problem revealed that most of these units have a well hidden factory setting to toggle the off switch to "instant off", which would cut the standby battery consumption to a fraction of milliamps. As Sod's law would have though, I can't find that setting on my (xTrons) head unit.

So my solution was to fit an SPDT (single pole double throw) on/off/on toggle switch unobtrusivly in the side of the radio binnacle housing.

This connects the radio's "accessory" power wire to either the radio's constant power wire (for occasional use with the engine off), or to a power wire that is live when the engine is running, so that it comes on when the engine is started, and goes off (completely), when the engine is stopped.

I must say, I'm impressed with the functionality of this relatively affordable head unit. It gives me my first automatic reversing camera, great audio from the full function RDS tuner, my entire music collection from a micro-sd card, and even OBD2 diagnostics from a cheapo blutooth ODB dongle. The double-din replacement dashboard binnacle housing was only obtainable from China, but it came within two weeks via Amazon, for £32.

 

[Vito61]

Thanks for all your input here.

I've got a Doblo 263 with, potentially, the same aftermarket connectivity issues. I had a Pioneer head unit installed many years that means I've lost the facility of being able to have the unit on with the engine off/key out.

Whether I go to this much effort to solve the issue remains to be seen. I suspect not. But It'll be logged away and maybe useful.