I am getting ready to install a Kenwood KMR-M312BT in a 2004 Crossfire I just purchased. I have read the sticky about using the VW harness to wire a head unit in, but was told by Crutchfield that the Metra harness would work exactly the same, with less work. I want to retain the factory amp, and told him so, and he said the Metra would accomplish that. The more I've read on this subject, the more confused I'm becoming. Has anyone here used the Metra harness, and if so did you retain usage of the factory amp?

 

I used "Metra 70-1784 Radio Wiring Harness for Audi 88-99/Volkswagen 80-Up " from amazon, I also got "Metra 70-1786 Radio Wiring Harness for Mercedes 94-04/Landrover 99-04 " and was trying different ways of connecting to the amp. I ended up just using the speaker wires from the front out of the Kenwood and did the best bang for the buck mod for the subs. While it isn't perfect, I would prefer separate controls for the subs, it is VERY nice sounding.
I also used "Metra 40-EU10 Antenna to Radio Adapter Cable for Select 2002-Up BMW/Volkswagen Vehicles " and "Metra 86-9001 Radio Removal Tool For Select 1998-2006 Volkswagen/Audi/ Mercedes "

 

Just had a pioneer DEH8700DAB installed and I didn't need any harness as one came with the unit so it was just plug and play. I did a lot of research and turned out I didn't need anything extra (well I needed a DAB antenna), luckily I was able to return it all. BTW it's a UK crossfire if that makes a difference.

 

Not sure if it does. I know other installs I've done, (granted its been a few years), required a harness. I would prefer the easier Metra, but want to retain the factory amp. I've been researching for days, but the only hits I get seem to redirect me to the forum.

 

You might be right as the fader function on my install has no impact on the rear speakers/subhoofer. On the plus side the new unit has specific subhoofer settings and sound great so all in all happy. Keep us posted as we may well follow your lead. And yes there are some open ended discussions on here and I do try to answer where I can to offer closure

 

A harness other than what comes with the radio is not required, but keeps you from needing to cut/splice into the factory wiring. Run the speaker out from the radio into the factory wiring and all will be well. You need to have power going to the blue wire for amp turn on. On some radios it is amp, other is it for power antenna, all the same, a wire that signals when your radio is on, and turns on something else. Get the 1784 instead of the 1786. And some different adapters use the red and yellow for opposite purposes, just follow pinouts and all is well.

 

Follow the PDF instructions, it works, so why do something that is not perfect?

 

Because I want to know if that's the best possible solution. I never take anything I read on the net for granted, I still do my own research.

Talked to the techs at Metra this evening, and if anything they have confused me more. They insisted to do it right I would not only need their harness, but also their ax-aloc608 adjustable converter. Reason being that the stereo I am buying isn't putting out 4v, more like 2v. They say that the converter allows a step up in voltage that will allow stereo to function correctly. Also was told that with the 70-1786 harness I would only need to hook up the grey and white RCA jacks as crossfires only operate on the front channel. Guy seemed to know quite a bit of specifics about the car. In the end I may do as the guy that wrote the PDF did and use the VW harness unless I find it incapable.

 

Understood, but I would rather not cut and splice original harness in case I decide to put factory original head back in.

Good to know about blue wire.

 

Sorry, I thought that you were putting in the same radio as I did that the PDF is about. It works fine so that is what I based my comments on. If it is basically the same my comments stand.
Sometimes you have to step back and reread the info you have found and sort the wheat from the chaff.

 

No worries. It is a Kenwood as you used, but a bit different model, probably not much difference. Had it narrowed down to this one, or the Clarion M502, but I don't think the 502 supports iPhone 6.

 

It's a bit different, but probably not enough to matter. Was also looking at Clarion M502, but it's not compatible with iPhone 6.

 

Doesn't really matter what the new radios is, most come with a connector with wires. Splice that to the Crossfire adapter and plug into the existing wiring.

That way you can always put the original but dumb radio back in. Downside is that it takes a little more of the minimal space behind the radio.

ps I just plugged my M303 in and even though hearing impaired (deef as a post) never need more than 1/2 way. Do have a Limited with amp.

 

Tried to reply twice to you with a picture of the deck, but for some reason it didn't work. Anyway, I've decided to go the route you described first, then if I need to I can always go the other way. Dad always told me when fixing something, always replace the cheapest part first and see if that fixes it. So by that logic, the VW01B is the cheaper route so I'll give that a shot first. Haven't ordered deck yet, but when I get it installed I'll update this thread with DB comparisons stock to aftermarket.

 

I replaced my OEM navigation radio with the Kenwood because of a whim, it is a lot of different from the old radios and one day I will have to read the manual for it.
I just use the radio anyway, but when my son came out with me before the change he always complained of the lack of extras on the head compared to the units he is used to.

 

My main impetus is the ability to have sirius radio.

 

As long as you buy a Sirrius XM ready radio you can buy a Sirrius XM receiver and it will be plug and play. I have this set up in both my Crossfires with Kenwood heads and they work just fine.

Jeff K

 

True. Ordering 300v1 tuner as well.