Hi Guys, I am in need of some help identifying the wires in the power iso connector on my fiat croma 2005. I am trying to fit an aftermarket head unit.
Please see pic named iso power_2.

The A connection power iso male from the loom has the following wires
1-Thin pink with black trace.
2-No wire,
3- Thin pink with white trace
4- Fat pink with black trace
5- no wire
6- No wire
7-yellow
8- black

In elearn, the pin out functions are shown for radio preparation as
A1,A2,A3 no connection
A4 +30 supply
A5 power aerial
A6 sidelight lighting
A7 +15 supply
A8 earth

Unfortunately I do not know the exact model of the original head unit as it was not in the car when I bought it. However Fiat eper gives a fiat part # fiat 735418045, which has a reference for blaupunkt 7645342316. However so far my searching does not revealed the pinout for this model head unit.

What I have is a 2Din chinese radio unit (model #7010b , unbranded) which uses the power iso connector to input the steering wheel control line. (See pic of line drawing with head unit pinouts)
Therefore the steering wheel controls do not work. Also this unit will not switch off.

I have tried a connects2 CTSFA003.2 steering wheel controls interface, but this is not compatible with this head unit. I am aware that the SWC wires are in the green mini iso connector and identifying the correct wire to feed into position of orange black steering wheel key control line of the head unit.

Any help and advice would be greatly appreciated.

Thanks.

Paul.

And a further scout of eLearn shows the power ISO connector as P020A

See Pic3

With this colour coding
A - light blue
B - white
C - orange
G - yellow
H - grey
L - blue
M - brown
N - black
R - red
S - pink
V - green
Z - violet

So I am a little confused because neither fiat elearn information describes my vehicles power connector, and I need to know what each of the wires are to repin the connector for my head unit.
Does anyone know where the wiring diagrams are in elearn, having real trouble locating it.
So if anyone has any experience of either 7010b head unit or is a wiz with radio wiring. I would appreciate any assistance.

Thanks in advance

Hi,
I'm not able to access my reference material at the moment, but the first issue you have to address is that the Croma (like most most modern Fiats) does not have a switched power supply to the radio. You can buy various adaptors that will provide this or you can tap off the cigarette lighter socket.
I don't think you will have much luck getting the remote control functions to work.

Robert G8RPI.

The thin pink ones are CanBus signal wires. You must not connect these direct to an aftermarket radio. (I wonder how long before aftermarket radios are made CanBus ready?)

As advised above, you can create your own wires from elsewhere, or fit an adaptor. Have a look at Autoleads and Connects2 websites for a better understanding. An adaptor fits between the car plugs and the radio and interprets the CanBus signals, creating analogue signals for the aftermarket radio. If you find the right combination (if it exists) you might also get a steering remote adaptor too. There are lots of similar threads on Punto Mk2. Grande Punto and Panda threads. So spend a tense afternoon trawling all that and hopefully it will make sense. Paracetamol may be necessary. (Other self-medications are available)

Hi Guys,
Thanks for your suggestions.

Robert,
On further investigation, I note that the switched live is already in place in the iso connector. I guess this was added to the original iso connector prior to my ownership when the original radio was replaced.. This explains the yellow wire on pin 7.

Nigel,
I spent a few hours with my head buried in elearn wiring and found that indeed the wires on in pins 1 & 3 are from the steering wheel controls ( and steering wheel air bag ). Fiat describe the original Power connector as

[FONT=&quot]"The radio P20 is supplied directly (pin 4 of connector A) from the battery via the line protected by fuse F23 of the engine compartment junction unit B001 .[/FONT]
[FONT=&quot]Pins 1 and 3 of connector A are served by the CAN that connects the radio to the Body Computer M001 (pins 24 and 25 of connector H) and to the other system nodes. Pin 8 of connector A is earthed.[/FONT] "

Prior to my original post, I had bought a Connects2 Steering wheel controls adapter (CTSFA003.2) apparently compatible with my 2005 croma, which did not work converting the SWC to work with the replacement head unit. This SWC adapters output ( Via patch lead) options to the head unit are by 3.5mm Jack, or 3 wire (ground, key1,key2) connections. The 7010b head unit has neither inputs available. There is a 3.5mm jack socket, but there is no written info on this being a patch lead input. Apparently there is a 5v out from this socket (suggested on another forum, unconfirmed by me)

I spoke to Connects2 technical support, about the SWC controls, and they informed me that the steering wheel control wires were NOT in this ISO power connector from the loom, and was in fact from the middle green mini iso block of the 20 pin block and thats were their product takes the feed from.
I know now, this is not the case for my 2005 Croma. :bang:

So I checked wires with a volt meter, in the Power iso and find that Pin 1 has approx 5v, and pin 3 has 0.5v, both of these were connected to my replacement head unit. Pin 1 on the head unit is for the reversing/parking sensor feature, and when connected to the original loom is fed by the SWC, So the head unit would not power off. Disconnecting pin 1 on the head unit allows me to turn off the unit.
Job Done .

Would be nice to get the SWC sorted out.
Pin 3 is still connected to the head unit as before.I have seen it reported on another forum when discussing this Head unit (7010b) and getting the resistor type SWC to work, a solution was to divert the disconnected Pin 1 to ground. However I tried this and this does not work either.

Can you tell me why, SWC canbus wire should not be connected to the head unit on pin 3, will this cause damage. I have no idea how long this head unit has been wired up this way.

If the SWC canbus wires are disconnected, I assume the loose pins should be insulated seperately, or should these be diverted. What is the reference to the steering wheel airbag and what are the effects if the canbus wiring circuit is now effectively broken.

CanBus are not power feeds, but signals. Whatever is on the receiving end interprets the signals to switch whatever was intended. Signals can be passed back along these to tell the ECU that things are happening as expected, or not. Whilst you may read a voltage, this is only to carry the signals. Sending unwanted voltages either way could cause damage to head or ECU. Not worth the risk. So far you seem to have got away with it.

Earlier ISO could contain extra wires for reverse signal (nav systems), lights on (display dimming), speed (nav). CanBus carry all these signals as codes and the head unit interprets them. I used to have a head unit nav system and used the CanBus adaptor to provide these signals to it.

Nigel,
Thanks for the explanation,

So, let me see if i get this straight.
For me to have the canbus working properly with SWC , I should either a)source a seconhand original radio unit or b) Change the 7010b to a branded 2Din unit with patch lead inputs via a canbus adapter to the original loom.
What Canbus adapter did you use ?

Paul.

An original unit would need its code, or the ECU will refuse to communicate with it - anti-theft.
If choosing an aftermarket unit and wishing to use the steering wheel controls, you need to do a lot of homework to ensure that a CanBus adaptor is available for it. These are available for most of the big brands, but unlikely for anything unusual, especially the Ebay sourced Chinese ones.

Connects2 is the best source, but autoleads are also useful.
http://www.connects2.co.uk/
http://www.autoleads.co.uk/
http://www.nexxia.co.uk/
http://www.incarconnections.co.uk/
https://www.dynamicsounds.co.uk/car-fitting-accessories.html

Do you recall the one you had fitted?,

Connects2 - only offer CTSFA003.2 adapter , and this option is for Punto Mk2 (Pre-canbus) and for Croma, I have tried this lead and this adapter does not collect the canbus signals from the iso male connector. ( According to their technical support.)

Auto leads - Have these items for the croma, listed on page 23 of their Steering wheel controls catalogue
FIAT CROMA 1986-2007 PC39-101 ( Canbus)
FIAT CROMA 1986-2007 PC39-110 ( Canbus),
But on Page 5 in the same brochure description it doesn't list this for the croma.
and the
FIAT CROMA 2006-2007 PC39-131 ( resistive)
FIAT CROMA 2005 -2007 PC99-X29 - (non-canbus)
but both are for resistor type.

If the 2005 croma is Canbus, then it confuses me that they should offer a resistor type.

Dynamic sounds - offer the auto leads product PC99-x29, and I bought the connects2 product from them even though they dont list it for the croma..

I have briefly looked at the other 2 suggestions, and have not located anything for the croma yet. I will make some calls to Autoleads about the adapters and see what they comeback with as an option.

Thanks again for your input..

Mine is a Connects2 CAN-01 universal interface, so no wheel controls. I can reach the radio easily, so not bothered. Purchased when the Corsa D was introduced, so late 2006. Used in several Corsas, then a Fiat 500, and now the Panda.

Hi,
There are a number of Croma radios on ebay at the moment. If you don't have the code, one of the moderators on here can get it for you. You have to make a small donation to the forum. See
https://www.fiatforum.com/i-c-e/85204-one-only-code-fiat-radio-thread.html?highlight=radio+code

Robert G8RPI.

Hi, I am Henk and new to this forum. About two months again I bought a Fiat Croma 1.8 from 2009. I wanted to replace the Blaupunkt unit with a Chinese aftermarket 2din system. It was a lot of work to find the right Canbus interface.
I tried four types from Connect2. The best result sofar gives the SFA004.2 harness with the Alfa Romeo interface. Unit works and I can use 3 buttons of the steering wheel control. (Volume Up, Volume down and Mute)

YAFUHENK said:

Hi, I am Henk and new to this forum. About two months again I bought a Fiat Croma 1.8 from 2009. I wanted to replace the Blaupunkt unit with a Chinese aftermarket 2din system. It was a lot of work to find the right Canbus interface.
I tried four types from Connect2. The best result sofar gives the SFA004.2 harness with the Alfa Romeo interface. Unit works and I can use 3 buttons of the steering wheel control. (Volume Up, Volume down and Mute)

Click to expand...

Hi Henk and welcome to Fiat Forum.
Thank you for the information on what interface worked for you, it will be useful for others who want to change their radio.
We did not hear more from Bigzed, I think his car had been modified from standard before he got it. This makes it very difficult to help without actually being at the car.


Robert G8RPI.