General Fiddling with the 500 single din radio - a couple of questions

[mj2k]

Yet another 'experimental, to be continued' thread, but whilst removing the boost gauge I had a little play with the single din radio in my Abarth 595 Turismo. The sound quality's not great and the radio signal quality is awful (I DO NOT want to spend all my time listening to Heart Radio! ) so decided to experiment with an old Sony media centre I had knocking around whilst the 'proper' stereo was sitting in the passenger footwell.

Looked straightforward but when I plugged it in, no power. This is because there's no direct switched (or unswitched) +12v supply to the DIN style stereo plug, it takes it's power from the CAN bus. This has 2 issues:

• No chance of using anything which doesn't take it's power from the CAN bus
• Draw too much power from the CAN bus (e.g. with a higher powered stereo) and that delicate i2c CAN bus wiring (or something more expensive) will go pop

However there's a normal ground, so for my experiment I simply ran a flying lead from +12v to the switched power input for the stereo, and plugged everything else in as normal. Much better sound quality, and it picked up 5 more radio stations. Still not perfect by a long stretch, but better. Fiddling with the roof aerial got a couple more, but still nowhere near as good as you'd expect. So looks like I'll be replacing the roof aerial with something a bit better, most likely the stereo too

Which brings me to 3 questions:

1. Anyone know what size the aerial hole is on a Fiat 500? I've noticed some rather nice amplified shark fins for sale in Germany (unlike the useless ornaments we have in the UK) which would look perfect and improve the signal, but need to know what size aerial I'd need. I can supply the answer to this myself in due course if nobody knows
2. Assuming I run a +12v switched power outlet to the DIN plug (I'll need it for the replacement boost gauge anyway, and the amplified aerial) are there any single DIN stereos around which can connect to the handy USB port near the gear lever, either with or without an adapter? Not too bothered about the steering wheel controls, though those would be nice to have.
3. I've seen lots of mentions of the speedo flashing if the standard radio is removed. Mine doesn't (or at least didn't during my 30 min fiddling), is this normal for a UK spec car or can I expect all hell to break loose at some time?

 

[mj2k]

Ok, well I'll answer all three questions myself

1. Aerial hole is a 20mm square (not round) hole, with a Fakra 2 aerial connector on mine (2015)
2. Nope. But I'm going to have a go at making an adaptor from the 20 pin Din C socket to USB plug and line in sockets, which would allow most to work
3. No problems at all with mine, took it for a 20 mile spin with the radio and boost gauge sitting in the garage - no flashing even in sport mode.

 

[ben]

Moved the guide to here - https://www.fiatforum.com/threads/removing-the-headlining-changing-the-aerial.491247/

thank you!

 

[mj2k]

Moved the guide to here - https://www.fiatforum.com/threads/removing-the-headlining-changing-the-aerial.491247/

thank you!

Thanks, I'll have to do a similar photo guide for removing the single din stereo too, if there's nothing similar around

 

[ben]

Thanks, I'll have to do a similar photo guide for removing the single din stereo too, if there's nothing similar around

Great

 

[mj2k]

Great

When done should I add it direct, or stick it in the original thread here so you can approve / move it as appropriate?

 

[ben]

When done should I add it direct, or stick it in the original thread here so you can approve / move it as appropriate?

Add it directly

 

[mj2k]

Add it directly

Done

https://www.fiatforum.com/threads/removing-the-single-din-blue-me-radio-and-top-vents.491250/

 

[ben]

Done

https://www.fiatforum.com/threads/removing-the-single-din-blue-me-radio-and-top-vents.491250/

Ah I just realised this new forum software doesn't have an image restriction on it - images for guides must be uploaded as attachments.

I'll modify it for you - and then look for some code that will solve that in the future - cheers!

 

[mj2k]

Just done a little bit more experimental research (it's Fri afternoon, work can wait ) and found some interesting things about the pinouts, which might come in v useful for a 3rd party stereo:

Connector A
Pin	Fiat	3rd Party
1​	CAN	n/c
3​	CAN	n/c
4​	Perm 12v	Perm 12v
7​	n/c	Ign 12v
8​	Gnd	Gnd

Connector B
Standard speaker connections, nothing to see here

Connector C
Sortof loosely based on the ISO pinout, but connections are all proprietary Fiat

Pin	Function
1​	Line out left (iPod media module?)
2​	Line out right (iPod media module?)
3​	Line out Gnd (iPod media module?)
7​	Tel AF + (if used)
8​	Tel AF - (if used)
9​	Tel Mute (if used)
11​	Gnd (if used)
13​	Data in (USB?)
14​	Data Out (if used)
15​	Perm 12v (if used)
16​	Ign 12v (if used)
17​	Data Gnd
18​	Aux Gnd (media port)
19​	Aux L (media port)
20​	Aux R (media port)

This info might be useful to making my 'adaptor thingy' to work around losing the nice USB media port and built-in functionality in the iPod media module.

Still need to check this out with a multimeter and make an adaptor for real but watch this space...

NOTE: I'm not planning to do anything with the steering wheel controls, they appear to be connected to the CAN bus, and I'm not too bothered about whether they function or not. But something like a Connects 2 interface will take care of that if you need it

 

[mj2k]

Checked the wiring on my Din C socket (A and B are as would be expected) and I have a subset:

Pin	Function	Colour
1​	Telematics Left	grey
2​	Telematics right	dark green
3​	Telematics Gnd	black
13​	Data in	purple
14​	Data Out	purple
18​	Headphone Gnd	black
19​	Headphone L	brown
20​	Headphone R	yellow

So if I ignore the headphone socket that means I just need one standard line in, and a USB port (assuming data in / data out are USB signals)

 

[mj2k]

Ooh, very interesting developments - just had a little play and managed to make a bluetooth Android phone call and play an MP3 file via the USB through an old 3rd party stereo just connected via pins 1-3 on the Din C socket to the stereo's line input

All the steering wheel buttons worked too except the stereo volume control (and selecting source outside the media module of course) so that means if you leave the Blue&Me module (Telematics module?) connected it takes care of pretty much everything. Right, time to find myself a good quality stereo for my other half to get me for xmas...

 

[mj2k]

I'm still awaiting the ISO socket to arrive which I need for reconnecting Blue&Me, but I added a nice, fresh switched +12v power supply lead to the ISO connector, and plugged in my new stereo for the first time (it's a Boss Audio - ugly and basic but reviewers rate the sound quality as better than many of the established big players in the head unit game, let alone the usual Chinese grot). Sadly the chip famine has affected supplies of high end stereos, so nothing fancier than the Boss coming for xmas for me

Nice new lead added using instructions here:


New front panel temporarily fitted, and stereo tested:

Radio reception massively improved even though I'm still waiting for the shark tooth aerial to arrive, and sound quality massively improved too, even with the standard speakers. So assuming I can get the existing Blue&Me connection working through the Boss' rear phono inputs (virtually nothing else new in stock out there with any form of rear line in at the mo, except the Boss), this will be a well worthwhile upgrade compared with the standard radio.

 

[mj2k]

Fitted the new shark fin aerial, annoyingly signal quality is every bit as poor as it was before, so not too sure what the powered amplifier does

Still, it looks nice, and it's got a built-in DAB aerial so I'm all ready for when the 'quality stereo' famine ends.

 

[A3jeroen]

Do you have 12V at the (probably) blue wire to the amplifier after switching the radio on?

gr J

 

[mj2k]

Do you have 12V at the (probably) blue wire to the amplifier after switching the radio on?

gr J

Yep, I've got it spliced into that extra switched +12v feed I added the other day, though connecting it to the 'power aerial' feed sounds like an excellent idea

Just doesn't seem like the aerial itself is terribly powerful - if I put my hand on it the signal of a very fuzzy station becomes crystal clear.

 

[mj2k]

Ohhhyessss!!!

Got the ISO C connector through the post today. Had to throw most of the wiring from it out and cut the 3 wires I needed to connect up to, but after a little soldering I was left with this:

Dropped it in, and it worked perfectly with the Boss stereo - MP3 via the USB socket, and calls via my phone (my phone stopped recording when it made a phone call, hence the sudden end to the recording).





And even better, the leads I needed to get it working arrived within hours of an absolutely ancient (10 years older than the car) Pioneer stereo - a DEH-77MP. Nice looking so it suits the Abarth dash much better, renowned for being very tough and long lived, and at the time it was made it had one of the best sound qualities around. Took a bit of fiddling to work out how to turn on AUX in, but once I did:





I'm a happy man now

BTW the Pioneer can be set to use 10Hz steps whilst tuning into a station, so I was able to pick up most of the stations I expected with good sound quality, simply by manually stepping down or up a couple of clicks. So no worries about the aerial after all, though it does make me wonder if the amp (or aerial) limits the signal spread so much the auto tuning can't lock onto stations with a perfectly good signal. Right, time to stop jumping around like a 10 year old on a sugar rush, I should have been in bed hours ago!