Amplifier - How Volvo adds it 9452029

PDLarson · Post by **PDLarson** » 09 Apr 2012, 19:59

I just completed an upgrade in my '99 V70XC from the SC-816 with no amp to a SC-901 with the under-seat amplifier pictured above. The biggest challenge was obtaining the 9452030 wiring harness (pictured above). It just takes time but I came across a used one. My other choice was to order the 6816303 harness which is still available for the 6816302 behind the radio amp and snip all the wires and add necessary length to all of them but thankfully, I didn't have to do that and I don't know if it would work or not.

Anyway, I just wanted to report that the entire job took about 3 hours.

To install the amp I unbolted the seat but just lifted it up and moved it back to give me some room to work. I DID NOT unplug any of the wiring to the seat. Installation of the amp is easy and just requires two flange screws. I went ahead and ordered 2 985186 for about $2.63 each locally from the stealer. I removed the center console. I'm not sure if I needed to but it probably did make the job easier even if it was not required. The carpet under the seat has three pre-cut holes. Just three of the four sides of a square are cut so there is a flap that can be folded out of the way when needed. The two smaller ones are for the amp mounting bracket and the larger one is for the wiring harness. The two smaller ones were hard to find, they are under where the inner seat rail would be. I simply ran the amp end of the harness under the carpet, through the larger hole in the carpet, connected to the amp and mounted the amp. Next, run the cable along the hump, outside of the center console but under the carpet. There are two holes here for the flat plastic part of the harness to snap into. Since mine was used, it was pretty obvious where it went, the wires had a memory and just sort of layed where they were supposed to go. The two plastic clips mentioned above and one other even matched up to holes in the car so it looks like the car came with the harness, my favorite kind of upgrade! To get the radio and car end of the harness up behind the radio, remove the old radio and just reach up behind the radio cavity from beside and above the hump, kinda' from under the glove box / mapholder area. Reach through the radio opening with the other hand and you can easily feed the harness through to your other hand into the radio cavity.

The connections are obvious, the amp end can only go one way (to the amp), the car end is basically, to the car speakers and the radio end, well, if you can't figure it out, maybe you should seek help with this upgrade

I did find that it was a little bit harder to get the SC-901 all the way into the radio cavity than the SC-816. I am not sure if this is because the 901 is a bit deeper, or maybe I didn't quite get all the new harness plugs out of the way. I tried my best to move all the excess cables and connectors out of the way and the radio just barely goes in far enough to close the clips on the side of the radio.

I have an iPod connector in the CD port so this works on CD6. Maybe this plug was interfering with pushing the radio all the way back but it was there with the 816 as well.

Anyway, the upgrade is complete and yes, it does sound way better than the 816 with no amp and I'm sure after reading the Rothe info, it is better than if I had bothered to try the 816 with an amp. It sounds great!

I am off to customize the EQ settings now...

chris9869 · Post by **chris9869** » 14 Mar 2014, 15:36

i read all the posts on this subject and it all sounds very technical but lets just say i have no electricary knowledge and am the proud owner of a 2004 s40 and in said car i whould like to replace the head unit with one i allready own (not volvo i'm afraid) but when its conected the sound only comes from front tweeters ,reading the forum lets me know its because there is an amp fitted to the car that requires the volvo head unit to run it but i whould like to either remove said amp and just run all the speakers from my stereo or find a way of just running the amp from my stereo either of these whould make me smile but like i said at the start (no knowledge) so pictures with arrows and colours whould be nice along with realy plain normal sentences like red wire to blue wire,
you all do a realy good job by helping people but i think i need a bit more help than normal people do

Post by **vjaneczko** » 14 Mar 2014, 16:09

First, I'd verify if you have an amp in your car. Next, I'd see if the replacement headunit has RCA jacks for output. If you have both, you can buy a wire harness that will allow you to connect your head unit to the Volvo amp (fairly) easily. The speaker wires provide a high power output while the RCA jacks provide a low power output. Some aftermarket amps allow you to connect both types but I'll bet the Volvo amp only accepts low-level input.

Not being familiar with the stereo setup of your car, I can only talk in broad strokes. You should also brush-up on some car stereo terminology if you're going to set this up on your own, just to make sure you don't accidentally make bad noises, such as "BZZZZZZZZZ", "PHHHHHHHHH" or "Holy crap, is that a fire?!" http://www.the12volt.com is a nice place to start, unless you know someone who works at BestBuy and can ask questions.

The head unit can provide power, rated in watts. The wattage is also tied to the ohm rating of the speakers. Most cars have 4 ohm speakers. but not all. You also need to be aware of how many speakers are wired in series and/or parallel for each channel (left/right/front/back). I mention this because the factory speakers & amp are probably designed to work specifically as one unit, and you may cause problems by removing the amp and wiring the speakers to your HU. The 850 wagon for example, has the front speakers wired in parallel but the rear were in series (or did I get that backwards?) Either way, it was a challenge to replace my HU and speakers, even without the factory amp in the mix. I had to run new wires to get it right.

If there's no amp, then you have to verify the speaker ohm rating and figure out all the wires that will connect the headunit to the speakers and make sure they're connected properly. That would be the 'red wire to blue/green wire' schematic you're looking for. Most of the time, you have to find the schematic for your headunit, then find the schematic for the car and create a diagram of what you have to do. If you get wire harnesses (and they're really worth the money), they should be able to help you figure out which wires connect to which.

If there's no RCA jacks on the headunit, it's the same thing; you'll have to disconnect the speakers from the amp and wire them directly to the headunit, removing the amp from the equation - not a great result.

There is one alternative but I've not used one; an adapter that allows you to connect the speaker wires (a high wattage output) to the RCA jacks of the amp (low wattage input).

chris9869 · Post by **chris9869** » 14 Mar 2014, 16:40

there is an amp and the head unit does have rca jacks (had to look up rca jacks on google)

Post by **vjaneczko** » 14 Mar 2014, 18:35

VERY Cool. Odds are pretty good you'll need one of these:
http://www.ebay.com/itm/Volvo-Stereo-Ra ... 0799250156

You can contact the guy that makes these to confirm which cable you need.

PDLarson · Post by **PDLarson** » 14 Mar 2014, 19:22

Some of the advice posted today is right on but you might also try posting a new question in the correct forum for your car. You might get answers more specific to your model in the right forum. This is for S70 and some other models thru MY 2000.

chris9869 · Post by **chris9869** » 15 Mar 2014, 03:00

this is true, thanks for the help evryone i shall now go back to my side if the fence

urmas97 · Post by **urmas97** » 23 Jan 2015, 04:23

Hello!

I have a Dolby Prologic system with SC900 in my 1998 V70. My rear door speakers have been getting pretty bad turning the last year. Before this they had quite a good punch, but now it's gone. I asked the dealer about replacing these speakers, but he told me that since the car is so old, he is not able to enter the database to what speakers fit into my car. He said that he can see only one kind of speakers to all of the V70. My question is that are Prologic system speakers different from regular V70 speakers?

Urmas

Post by **vjaneczko** » 23 Jan 2015, 06:52

Probably, but anything is better than what you have at the moment. It'll be cheaper to buy something from Amazon or your local electronics shop and install them yourself. The quality won't be much different than factory. Just verify the ohms and you're good to go.

PDLarson · Post by **PDLarson** » 23 Jan 2015, 07:52

No, the're the same. There was a Dynaudio variant but that's an upgrade kinda' like some Chevys have Bose speakers. Dynaudio speakers for these cars haven't been available for many many years.

The prologic is an extra decoder box under your dash behind or near the head unit and adds the center speaker in the center of the dash. The rest of the speakers are the same.

I have pics of my standard OEM (non-Dynaudio) speakers here
http://www.dplarson.net/volvo.html

Amplifier - How Volvo adds it 9452029

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