850 radio swap.

Post by **rguzz** » 28 Nov 2016, 04:26

Have the basic head unit without CD but would like to swap it out for the Volvo one with CD player in dash. Is this a direct swap or do I need to alter the harness behind the unit?

Post by **Ozark Lee** » 28 Nov 2016, 05:38

Plug and play for most radios. The SC901 units require that an amp is in place but most of the others can be swapped out in about 5 minutes.

...Lee

Post by **rguzz** » 28 Nov 2016, 07:32

Thanks, Lee.

Post by **JimBee** » 30 Nov 2016, 11:12

Do I have an amp but don't know it?
To test a recent JY acquired Premium Sound System unit (works great!), I pulled the installed CD/tape/radio unit and voila! there's a cable plugged into the amp socket. But where's the amp? The cable, wrapped in the foam used on the other radio harness, disappears upward to the left by the cluster. I thought the amps on these cars sat behind the radio.
Maybe that's somehow related to the smaller "hockey puck-like" thing dangling under my dash behind the cluster. There is a spool of insulated wire taped to the HVAC unit behind the radio that, from memory, looks like what's connected to the hockey puck. Any thoughts?

Post by **BEJinFbk** » 30 Nov 2016, 14:21

JimBee wrote:Do I have an amp but don't know it?
To test a recent JY acquired Premium Sound System unit (works great!), I pulled the installed CD/tape/radio unit and voila! there's a cable plugged into the amp socket. But where's the amp? The cable, wrapped in the foam used on the other radio harness, disappears upward to the left by the cluster. I thought the amps on these cars sat behind the radio.
Maybe that's somehow related to the smaller "hockey puck-like" thing dangling under my dash behind the cluster. There is a spool of insulated wire taped to the HVAC unit behind the radio that, from memory, looks like what's connected to the hockey puck. Any thoughts?

You sure it's the AMP and not the CD socket?
Also, if you have a factory amp, in addition to the 6 pin DIN cable,
you'd also have one of the two main connectors almost completely
empty of the wires that feed the speakers from an internal amped HU.

Post by **Ozark Lee** » 30 Nov 2016, 15:45

The hockey puck and the spool are likely from the tweeters in the dash. The magnets have a nasty habit of falling off and sometimes the voice coil comes out with it.

The fact that the radio says "Premium Sound System" really doesn't mean anything. There were a few variants of the SC-815 and SC-816 that needed an amp but they are few and far between. The SC-901 needs the amp for sure. Even the 816 system that I have in the Platinum that does have an amp had a head unit that would drive the speakers without the amp being there.

...Lee

Post by **JimBee** » 30 Nov 2016, 19:10

Interesting, about the hockey puck like thing. I'll have to check it out for magnetism.

I checked and the cable in question appears to have the CD connector. But if the radio has a CD built into it why would is there a cable for the CD port and where does that go?

Also, I checked the SC #'s. I have the 815 (stamped Premium Sound System) and the 816 which doesn't have a style name. Are they both the same unit?

Aside question. The 815 came from a car that looked like it had been left in a farm field with the windows open for a year. Thus, the 815 face plate is filthy. Does it come off simply as it appears without possibly damaging anything fragile behind it?

And one of the slide locks on the side doesn't lock. Those don't look fixable. That's just a junk yard pull from a trashed radio.

Post by **BEJinFbk** » 30 Nov 2016, 19:27

Many of the SC series had a 6 disc changer option.
Most of the time, the car came prewired with the
changer cable in the car that runs to the changer's
location in the back.

AFAIK, the SC-815 and SC-816 are virtually the same
HU with different color faceplates for 850's or x70's.

The hockey puck and associated wires? Pics, man - PICS!

Post by **rspi** » 01 Dec 2016, 02:02

Some of the faceplates are interchangeable.

The Premium Sound System has a more powerful built in amp and does sound better.

101 · Post by **101** » 01 Dec 2016, 14:48

If you have a CD cable plugged into the back of your current head unit - the other end is usually found in the trunk area where an accessory CD changer would mount. It was nice of Volvo to pre-wire that for us.

AFAIK, the SC815 and SC816 is the same exact thing with different color face plates.

Both the SC815 and SC816 can be used without a Volvo amplifier. I believe the base power of both of those units is 25W per channel. If you add the Volvo amp, it bypasses the head unit's internal amp and the power increases to 40W per channel or 50W per channel, depending on the amp model that is installed. The Volvo amp lives between the radio and the heater core on 850's and S/V70's that came without the SC900/SC901.

The SC900 / SC901 requires the external amp to operate. There is no internal amp on those models. The Dolby processor and center speaker can be added to these, but it is not required.

I rock the full SC901 / Dolby setup in my wagon and an SC816 with a 50W Volvo amp in the T5.