P80 Radio wiring help needed

Post by **scot850** » 10 Apr 2016, 14:18

I am trying to add an Ipod/Aux input to my Volvo SC-901 head unit. The interface is a USA SPEC PA11-HON unit with the correct Volvo wiring harness. This is supposed to work with SC-XXX radios, and after corresponding with both USA SPEC and Crutchfield they both say this should work as I have the external CD changed option on the head unit.

My car (2000 V70R) has an external Volvo 6CD unit installed but it is fitted into the glove-box almost completely making it useless for storing anything else like my traffic cam or Garmin.

As I barely use the 3CD in-built unit in the radio as it is, removing the 6CD unit is no great loss so I can use the CD output on the head unit for the adapter.

Theoretically all that is required is to remove the external CD cable and plug in the USA SPEC cable, and then connect x 2 wires to the existing harness.

The 2 wires are:

1) Constant live (+ve) to the battery.
2) Switchable live (+ve) from ignition.

I have done this but when I press the 6 CD option on the head unit nothing happens. If I plug the 6 CD player back in it works fine.

The options for the 2 wiring connection I believe are:

1) Constant live (+ve) - Pins A4 and A12 if I read the wiring harness info correctly (both black wires)
and
2) Switchable live (+ve) - Pin A13

I have tried both but nothing.

So options are:

1) USA SPEC unit is faulty (bought 2nd hand but supposedly unused)
2) There is a note on the Crutchfield web-site saying the unit does not work with head units with internal SC players. They did say from seeing the output on my head unit it should work.
3) I am using the wrong wiring points.
4) The Volvo wiring for the 6 CD option uses a 2nd adapter wiring insert in the AMP loom from where it ends to the back of the radio to add in 2 extra wires. An earth (pin A6) and a live to A4. Perhaps if I remove the insert loom maybe it may work?

Any thoughts are appreciated.

: 6 CD changer in glove box

: 6 CD wiring harness insert

: 2 wires for 6 CD option

101 · Post by **101** » 10 Apr 2016, 15:08

I have this exact same setup in my car. SC-901 head unit, 6CD glove box changer and the USA Spec adapter.

I swap between the 6 CD changer and the USA Spec options depending on my mood. I keep the connector accessible in the glove box. All I have to do is disconnect the cable from the changer (its about 6" from the changer) and plug in the cable from the USA Spec box instead. It works perfectly.

Whatever power or ground the CD changer Volvo harness insert is tapping into at the back of the radio is exactly what the USA Spec requires. Try utilizing that harness instead of the USA Spec one and see if USA Spec adapter works. I have had issues with the supplied USA Spec cable on another car.

Let us know what you find out.

Post by **scot850** » 10 Apr 2016, 16:13

Thanks 101. Glad to hear you have this working. Just one clarification. Do you just swap the cable where they join in the glove box with no other changes? Do the 2 'extra' wires for the USA Spec unit that I mention use the same connections? If so that would explain the problem as the 2 spare wires Volvo 6 CD player use are 1x constant +ve connection and one earth (as used on the P2 version), but the USA Spec unit says to use 2 x +ve connections (a live +ve and a switchable +ve.

Is it at all possible you can take a picture and post it how you connect the wiring in the glove box?

Many thanks,

Neil.

101 · Post by **101** » 10 Apr 2016, 18:09

Neil:

Correct. I just swap the connection in the glove box. I did not use the USA Spec supplied cable that plugs into the Volvo radio with the two additional connections required.

PM me your email address and I'll take a few pictures tomorrow or Tuesday. I'll also send you a closeup of how the DIP switches are set on my USA Spec. I'm only using it for the aux input as the iPod control cable is long gone.

Keith

Post by **erikv11** » 10 Apr 2016, 20:15

I've also got a similar unit installed in my 95, works great. All I did was "remove the external CD cable and plug in the USA SPEC cable, and then connect x 2 wires to the existing harness." It is an SC-8xx radio, though. The 6 CD player is still in the trunk, didn't do anything with its harness. If you need more pics let me know, I can get them.

Post by **scot850** » 10 Apr 2016, 21:34

Thanks guys for all your help. 101 I'll PM you for those pictures when you get a chance. Not urgent.

erik11 also appreciate your help. I happen to have 2 x SC-8XX radios and codes in my stash with the other SC-900/1's in my stash of stuff. If I have no luck with my current radio may try the SC-816. But as 101 seems to have the same set up it makes me wonder if I was sold a pup.

Neil.

Post by **BEJinFbk** » 10 Apr 2016, 21:43

Battery = Pins 4 & 12 - Brown/Green
Switched = Pin 13 - Yellow/ Violet
Ground = Pins 6 & 14 - Black

Post by **scot850** » 10 Apr 2016, 23:09

Thanks BEJ.

You have confirmed what I had figured out. But what is confusing, is 101 says he is swapping the lead for the 6 CD changer over with the USA Spec adapter. The thin is the 2 'spare' wires that have to be connected are different. Both use a 12V constant/battery (pins 4 or 12) but then the USA Spec adapter says to connect the other wire to the switchable +ve (pin 13). The 6 CD uses a ground on pin 6. So how does this work? Wiring it the way that USA Spec says definitely doesn't appear to, so tomorrow I will try 101's method.

If I can get it to work, then I planned to try it with 3 other Volvo radios to see if the same wiring works for hose also. If it does or whatever I find I plan to post it up on MVS for others.

Appreciate your help from the more frozen North!

Neil.

Post by **BEJinFbk** » 11 Apr 2016, 00:25

AFAIK, the remote changer only gets batt and ground.
I couldn't tell you what's going on in 101's situation.
It sounds like he's using batt for both leads.
Fine if you don't leave it plugged in all the time,
but if it's connected that way permanently, you
may run into parasitic draw problems.

I'd just keep it simple and connect at the HU
with batt and switched as USA Spec indicates.

Post by **scot850** » 11 Apr 2016, 07:45

I am confused, as I said I tried the 'correct way' and nothing. When 6 CD option was selected nothing happened. Pressing the button resounded in a big fat nothing. So maybe the unit I was sold 2nd hand has been fried by the PO?

The version for the P2 model HU's uses a live and ground, rather than a live +ve and switched +ve. Good point that this could give a parasitic draw, but I could measure that and see if it happens. Surely though, if it doesn't appear to need the switched +ve then why have it?

Maybe there is more to using the SC-900 or 901 in terms of differences to SC-816. Maybe they are more like the P2 HU's.

Hm...

Let you know later what happens.

One other question, there are 2 dip switches on the side of the USA Spec unit. I understand the use of #1 and it's setting, but what should the #2 be set to?

Neil.