Technical Ongoing Barchetta stereo wiring problems

[Unionfan]

This week's challenge seems to be to find a way of ensuring our new stereo will turn on and off when it should and stay turned off when we turn it off!

I've posted elsewhere about paying a bit more for a head unit with a dedicated Barchetta wiring harness and adapter BUT it turns out that even these won't work if your car's wiring is not as per the factory manual's wiring diagram! I've no idea why our car seems to be different but here goes.

The wiring diagram for the radio (head unit) is attached (supplied by @Wiltshire Chris here: https://www.fiatforum.com/downloads/service-manual-restructured.410/ . Thanks again). It shows that there are two constant lives coming out of the junction box (red and black) and one live from the ignition circuit (yellow and black). Plus an earth which leads to the car's left side earthing point. There is one other wire that doesn't seem to go anywhere but on our car it is yellow. So far so good and you would think that this would work for a matching wiring harness....

However, our new stereo has never worked properly in terms of only working when the ignition is on, remembering any presets or settings and even staying turned on once you've started the engine. So, I've run a volt meter across the terminals on the car's wiring 'plug' containing all the wires outlined above and the results are confusing....

• Both red and blacks are constant lives as expected when tested with the black (which made me think the earth was working properly)
• The yellow and black ignition circuit which I thought was supposed to be live when the key is turned to 'dashboard lights all on' position is dead all of the time when tested with the main, black earth. Tested this with the engine running too and got the same result.
• The solitary yellow wire also shows zero volts when paired with the black earth whether the ignition is on or off.
• If, however, you pair either of the red and black wires with the yellow and black or the yellow wire, the meter shows 12 volts whether the ignition is on or off, so these are making a circuit somehow.

I've also attached a diagram of the terminals in the wiring 'sockets' for reference.

I've checked as many relevant fuses as I can find and am now completely stuck. I'm waiting for some feedback from the In Care Emporium but am worried that if I share the above information with them, they'll just tell me the problem is with the car and not their dedicated kit.....

If anyone has any ideas on how to get the yellow and black wire from the ignition circuit to actually show some volts when it should, (or indeed any other ideas) I'd be very grateful.
Thanks in advance
UF

 

[Wiltshire Chris]

The wiring diagram for the radio (head unit) is attached (supplied by @Wiltshire Chris here: https://www.fiatforum.com/downloads/service-manual-restructured.410/ . Thanks again)

No worries, I just re-organized the original scans, very grateful to whoever did the original scans.

Mine might be doing something similar. I've a feeling mine doesn't properly turn off with the ignition and that may be because the installer gave up on the ignition live. I'll pull my head unit out when I get a chance and do some wiring checks too. Too cold today to spend long in the garage

 

[Unionfan]

No worries, I just re-organized the original scans, very grateful to whoever did the original scans.

Mine might be doing something similar. I've a feeling mine doesn't properly turn off with the ignition and that may be because the installer gave up on the ignition live. I'll pull my head unit out when I get a chance and do some wiring checks too. Too cold today to spend long in the garage

Thanks as ever Chris. If the head unit isn't connected properly, it will only end up draining the battery! I have a catch up with the ICE technical team later today and will update the post if there's anything to share. And it's freezing here today too!

 

[Unionfan]

And to add to the wiring diagram confusion.... Here's an extract from the radio page:

The box marked 31 is the 'junction unit' which I'm assuming is the fuse box housing the inside fuses and relays (could be wrong). In box 31 the two vertically bracketed numbers of 10 and 2 represent fuses but I don't know if the 10 and 2 represent amperage of the fuses or their position? Either way, it doesn't relate to what I can see in that fuse box (underneath and to the left of the steering wheel). I'm just trying to find out why that yellow and black wire (marked GN on the diagram) has no juice when it looks like it's supposed to come from the ignition switch which is marked 33.

Does anyone know where that ignition switch actually is please? On the diagrams it looks like it's behind the instrument binnacle, in which case I'm not going to bother dismantling the whole thing just to get the stereo to work

Kevin

 

[Unionfan]

And here's the location diagram of those boxes...

 

[Wiltshire Chris]

Hello, I just did a little bit of testing on my B which pretty much echoes your results. Looking at the ISO standard for the connector:

On my car
A1, A2 and A3 aren't connected
A4 is Red and black and gave a constant 14V
A5 is Yellow
A6 is Yellow and Black and possibly gave a very small amount of mV which might be valid for the illumination???
A7 is Red and Black and gave a constant 14V
A8 is Black and is clearly the ground

So the ISO standard is that A7 should be switched. The wiring diagram clearly shows that this isn't the case as it is connected to A4 in junction unit 31J

Sorry, that hasn't moved the game forwards very much but just agrees with you. I'll try to dig further...

 

[Wiltshire Chris]

Found a bit on fuses for what it's worth
Fuse layout:

Fuse 2:

Fuse 10:

 

[ernibv]

This week's challenge seems to be to find a way of ensuring our new stereo will turn on and off when it should and stay turned off when we turn it off!

I've posted elsewhere about paying a bit more for a head unit with a dedicated Barchetta wiring harness and adapter BUT it turns out that even these won't work if your car's wiring is not as per the factory manual's wiring diagram! I've no idea why our car seems to be different but here goes.

The wiring diagram for the radio (head unit) is attached (supplied by @Wiltshire Chris here: https://www.fiatforum.com/downloads/service-manual-restructured.410/ . Thanks again). It shows that there are two constant lives coming out of the junction box (red and black) and one live from the ignition circuit (yellow and black). Plus an earth which leads to the car's left side earthing point. There is one other wire that doesn't seem to go anywhere but on our car it is yellow. So far so good and you would think that this would work for a matching wiring harness....

However, our new stereo has never worked properly in terms of only working when the ignition is on, remembering any presets or settings and even staying turned on once you've started the engine. So, I've run a volt meter across the terminals on the car's wiring 'plug' containing all the wires outlined above and the results are confusing....

• Both red and blacks are constant lives as expected when tested with the black (which made me think the earth was working properly)
• The yellow and black ignition circuit which I thought was supposed to be live when the key is turned to 'dashboard lights all on' position is dead all of the time when tested with the main, black earth. Tested this with the engine running too and got the same result.
• The solitary yellow wire also shows zero volts when paired with the black earth whether the ignition is on or off.
• If, however, you pair either of the red and black wires with the yellow and black or the yellow wire, the meter shows 12 volts whether the ignition is on or off, so these are making a circuit somehow.

I've also attached a diagram of the terminals in the wiring 'sockets' for reference.

I've checked as many relevant fuses as I can find and am now completely stuck. I'm waiting for some feedback from the In Care Emporium but am worried that if I share the above information with them, they'll just tell me the problem is with the car and not their dedicated kit.....

If anyone has any ideas on how to get the yellow and black wire from the ignition circuit to actually show some volts when it should, (or indeed any other ideas) I'd be very grateful.
Thanks in advance
UF

After thinking about it a bit: Modern car radios are wired differently than 20 years ago. The radios are also different.
That said: My purchased last year 2001 B was wired with a CD changer in in the trunk. If I turned the car off, but not the radio, my battery would be dead in the morning. Took me a bit to figure out that the radio was the problem.
A modern radio is wired to turn off via the ignition switch, but maintain memory and pre-sets. So it's a choice. When's the last time you listened to your radio in the car ?
grtz
Eric

 

[Wiltshire Chris]

Just to add a small bit of information for posterity.
Pin A6, the yellow and black wire is +12V when the headlights are on, which makes sense when you think about it.

I'm going to amend my wiring slightly and run a relay to make pin A7 switched +12V on the ignition. There's a handy switched +12V feed (orange wire as detailed here https://v4.barchetta-lexikon.de/index.php/lexikon/d/digitaluhr ) going to the clock which I shall splice into to drive the relay and then route the existing A7 wire through the load side of the relay. Hopefully that should avoid battery drain when the ignition is off.

 

[Unionfan]

After thinking about it a bit: Modern car radios are wired differently than 20 years ago. The radios are also different.
That said: My purchased last year 2001 B was wired with a CD changer in in the trunk. If I turned the car off, but not the radio, my battery would be dead in the morning. Took me a bit to figure out that the radio was the problem.
A modern radio is wired to turn off via the ignition switch, but maintain memory and pre-sets. So it's a choice. When's the last time you listened to your radio in the car ?
grtz
Eric

I listen to the radio all the time in the Barchetta during the summer as it's the best way of avoiding traffic problems here in SW France . But you're right, it's not difficult to find a station again The most annoying issue is the worry about whether the battery will be drained by the head unit.

 

[Unionfan]

Just to add a small bit of information for posterity.
Pin A6, the yellow and black wire is +12V when the headlights are on, which makes sense when you think about it.

I'm going to amend my wiring slightly and run a relay to make pin A7 switched +12V on the ignition. There's a handy switched +12V feed (orange wire as detailed here https://v4.barchetta-lexikon.de/index.php/lexikon/d/digitaluhr ) going to the clock which I shall splice into to drive the relay and then route the existing A7 wire through the load side of the relay. Hopefully that should avoid battery drain when the ignition is off.

Good luck with your work-around.... too complicated for me I'm afraid and I'm going to have to try and find an auto-electrician to make it work properly I think. Thanks all.

 

[tjr]

Just to add a small bit of information for posterity.
Pin A6, the yellow and black wire is +12V when the headlights are on, which makes sense when you think about it.

I'm going to amend my wiring slightly and run a relay to make pin A7 switched +12V on the ignition. There's a handy switched +12V feed (orange wire as detailed here https://v4.barchetta-lexikon.de/index.php/lexikon/d/digitaluhr ) going to the clock which I shall splice into to drive the relay and then route the existing A7 wire through the load side of the relay. Hopefully that should avoid battery drain when the ignition is off.

Thanks to OP & posters for digging into the electrics from a posterior!

Hmm, the "good to have" projects are starting to pile up..., but do please share what relay you end up choosing!

 

[Wiltshire Chris]

I used a Bosch 0332019110 relay. All my relay knowledge came from reading:

Automotive Relay Guide | 12 Volt Planet

Read our guide to relays found in vehicle electrical systems. How they work, why they're used and some example applications

www.12voltplanet.co.uk

and

DIN 72552 - Wikipedia

en.wikipedia.org

I used insulated spade connectors and some short lengths of wire to connect the black and orange wires to the clock to terminals 85 and 86 of the relay. Rather than doing it all properly I just wedged the wires into the connector block on the clock. I should probably have stripped the wire and soldered them on but I was being lazy.

For the radio end I could just use the adapter loom that came with the radio to intercept the wire going to pin A7 and take it via terminals 30 and 87 on the relay. The A7 wire on my adapter already had a bullet connector at the midway point so I used this to divert to the relay (the red wire below):

Now with my new slightly chunky new orange wires going off to the relay:

The wires ran down the back of the heater controls and could be fished out from underneath the clock hole as shown in the first picture. After attaching them to the relay I it into the hole and put it all back together.
The radio now turns off with the ignition but remembers its state so that when you turn it back on the same track is playing from the USB

Hopefully this should mean that the battery doesn't go flat now but only time will tell if that has worked.

 

[tjr]

@Wiltshire Chris the lcd-screen clock is slowly going black, a used replacement (not yet tested) has arrived, a car stereo is waiting to be installed (w speakers), and I want to follow your A7-clock steps, thanks again for sharing!

Before going through the process; do you/anyone know the Amperage being fed to the car stereo A7? If only a +12V (minimal amp) signal; couldn't A7 simply be fed off from the orange +12V signal going to the clock (replacing the constant +12V black/red (and thereby omitting the need for a relay))?

(Oh and Oh Joy, the heater matrix has started the dreaded trickle (sending a warm sweet scent into the cabin)... Here's me trying unsuccessfully to come up with reasons to avoid doing it at the same time...)

 

[Wiltshire Chris]

@tjr you might well be right but I thought the wire going to the clock looked quite thin and so, possibly in ignorance, decided to use a relay just in case. It'd be a lot easier if you can just feed straight from the orange wire. Sorry to hear about your heater, I dread that happening too
Good luck with it all

 

[tjr]

Thanks @Wiltshire Chris x2. At least it was heaps better finding out about it in the garage on a winter day than speeding on a winding road at night in midst of winter (when skimping on antifreeze...).

Concerning the clock-A7, the safe bet is going via a relay. I was unable to think up good search terms for finding facts on the matter, so I ended up mailing Pioneer hoping they might respond (sometime soon)..!

EDIT:
Pioneer were quick to respond, they claim (no responsibility) their equipment only needs +12V for signal from A7 (ISO), so thin, low amp, wire would work. He wrote they normally suggest taking the signal from the lighter wire (switched on the b?). The rep had no issues taking the signal from the clock wire, pondering the possibility that it might affect the clock.

 

[Unionfan]

I used a Bosch 0332019110 relay. All my relay knowledge came from reading:

Automotive Relay Guide | 12 Volt Planet

Read our guide to relays found in vehicle electrical systems. How they work, why they're used and some example applications

www.12voltplanet.co.uk

and

DIN 72552 - Wikipedia

en.wikipedia.org

I used insulated spade connectors and some short lengths of wire to connect the black and orange wires to the clock to terminals 85 and 86 of the relay. Rather than doing it all properly I just wedged the wires into the connector block on the clock. I should probably have stripped the wire and soldered them on but I was being lazy.
View attachment 421943
For the radio end I could just use the adapter loom that came with the radio to intercept the wire going to pin A7 and take it via terminals 30 and 87 on the relay. The A7 wire on my adapter already had a bullet connector at the midway point so I used this to divert to the relay (the red wire below):
View attachment 421944
Now with my new slightly chunky new orange wires going off to the relay:
View attachment 421945
The wires ran down the back of the heater controls and could be fished out from underneath the clock hole as shown in the first picture. After attaching them to the relay I it into the hole and put it all back together.
The radio now turns off with the ignition but remembers its state so that when you turn it back on the same track is playing from the USB
View attachment 421946

Hopefully this should mean that the battery doesn't go flat now but only time will tell if that has worked.

Wish I had your skills Chris Ours still works after a fashion but I can't do what you did... I don't suppose you fancy a free stay for a few days in the west of France do you in exchange for your skills? Kevin

 

[ernibv]

How far south and west are you in France ? We're planning a drive down to Normandy from Amsterdam in the b in April.
grtz ER

 

[Wiltshire Chris]

Wish I had your skills Chris Ours still works after a fashion but I can't do what you did... I don't suppose you fancy a free stay for a few days in the west of France do you in exchange for your skills? Kevin

That's a very kind offer, thank you, sadly we're confined to the Uk for the time being due to eldery parent issues but I have an ambition to drive the B across Europe so I'd happily drop by but you might have to be very patient!
Is there not an auto electrician anywhere local who could follow the notes in this thread to get you sorted?

 

[Unionfan]

That's a very kind offer, thank you, sadly we're confined to the Uk for the time being due to eldery parent issues but I have an ambition to drive the B across Europe so I'd happily drop by but you might have to be very patient!
Is there not an auto electrician anywhere local who could follow the notes in this thread to get you sorted?

Hi and sorry to hear about the family; hope all is well on that front. The local auto-electricians specialize in French brands and when I explained that the car's reality didn't match the factory manuals they didn't want to even try Even the Fiat dealer here just giggled and said the French equivalent of "what did you expect, it's a Fiat", which made me laugh out loud . We'll get there. And you'd be more than welcome to pop by as and when you have the inclination and opportunity