Before hooking up the connectors from the console, one should make the fiber optic and power connections to the GW 500, because the short length of wires from the console leaves little to work with. Now for the really fun part. First, remove the COMAND unit as discussed above. After removing the four screws (#20 Star driver), it just slides out, Do not kink the orange fiber optic leads – doing so can ruin them.
The Dension installation guide (available on the Dension support site,
Dension - Support) is very badly written. Its diagrams are small, and the text is inadequate. The diagrams for fiber optics, which show the light path, indicate that the GW 500 is to be installed immediately ahead of the CD changer in the fiber optic ring. This is easy to do with a CDC mounted in the passenger compartment; but for a trunk-mounted CDC, it becomes much more difficult. The text does not address the positioning of the GW 500 in the MOST ring at all. Therefore I connected it ahead of the CDC in the ring, but not immediately adjacent to it, because no work must be done in the trunk that way. More below.
One must be very careful to connect the fiber optic leads in accordance with the direction of light travel; arrows are molded into the ends of the connectors showing the direction.
On the back of the COMAND unit there is a single large connector with both the power wires and the fiber optic leads. Remove the connector by pushing down on a spring release at the top center of the connector as shown in the first photo below.
Once the large connector is out, release the tab on the left side of it to release the smaller fiber optic connector, shown in the second photo below. Note the arrows at the end of the connector.
On the side of the connector with the arrows are two slits; after removing the small blue retaining plug, insert a fine blade or screwdriver tip, twist slightly to spread it, and gently pull the fiber optic lead out - see third photo, below. For my installation, I disconnected the output lead from the COMAND unit in order to insert the GW 500 ahead of the CD changer in the fiber optic loop. Then placing fiber optic leads into the connectors, push in gently until hearing a slight "snap" then replace the blue retaining plug.
Here is one place things get complicated. The fiber optic diagrams showing connection of the GW 500 directly to the CD changer in the installation guide are probably OK (though the text tells you very little) if you have a CDC in the passenger compartment (probably in the glove compartment). In that setup, breaking the fiber optic loop at the CDC places the GW 500 immediately before the CDC in the fiber optic loop. However, this diagram is practical only for CD changers mounted in the passenger compartment. Follow the rest of the diagrams in the guide to complete the connections.
Here's why it isn't ready for prime time. The diagrams don't work for a trunk-mounted CDC. Unfortunately, for a trunk-mounted CDC, the only place to put the GW 500 is either with the light coming out of the COMAND unit, or going into it. This does not allow placement of the GW 500 in the fiber optic ring
immediately before the CDC. The installation guide is silent regarding this physical setup (GW 500 immediately before the CDC); only the diagrams suggest it. Placing the GW 500 on the output side of the COMAND unit inserts the GW 500 before the CDC, but not adjacent to it. Placing it on the input side places the GW 500 after the CDC. And right now, with my GW 500 inserted before the CDC, but not immediately before it,
my GW 500 does not work!! It also won't work if installed on the input side to the COMAND unit (after the CDC). I tried. (NOTE: See post #5 below. Suspicions correct - the GW 500 must
immediately precede the CDC in the fiber optic loop in order to work).
The fiber optic connections to the GW 500 unit are in fact simple, but the illustrations are poor. What they (and the text) fail to tell you is that a protective cover (with holes, no less) that looks like a connector but will not fit any of the connectors supplied, is installed in the fiber optic socket of the GW 500 box. This protector must be removed before any fiber connections can be made to the box. Once that is done, the rest of the connections become fairly easy to follow. You use a 2-piece socket - a larger part fits into the GW 500 box, and a fiber optic plug then fits into that.
Despite all wiring and fiber optic leads being properly installed and connected, and checked and rechecked as correct, the GW 500 starts my iPod up, but does not replace the CDC on the fiber optic bus. The iPod starts up and begins to show the Dension intro pages; but then it starts playing the last song I was playing before starting up. The CDC remains connected, plays over the audio system, and displays in the COMAND screen, The iPod does not. I am informed by forum contributor Rob13572468 that this problem has occurred for him in GW 500 MOST installations, and may require removing and reconnecting fiber optics in the trunk so that the GW 500 and CDC fall into the right sequence. Rob is researching exactly which connectors to move in my car – the physical connection sequence may or may not match the fiber optic ring diagrams in the phone bulletins on Paul H. Dick’s site (
http://home.earthlink.net/~phdwebsit...bulletins.htm). If they do, the solution is to switch the F/O connections (not power or anything else) between the Voice Control Module and the CD changer, which would put the GW 500 in the right sequence, immediately ahead of the CDC in the fiber optic ring. A real pain!!
MORE TO COME.
The last thing to do is to tap into unswitched 12v power and ground wires – either those going to the COMAND unit, or by adding a fuse holder on the dashboard panel and tapping into ground. To do the latter, run the power wires to the front fuse panel and use one of the unused fuse slots and also connect to the ground point in the kick panel (there is a 10 mm bolt with ground wires terminating there). (Thanks to Rob13572468 for that information). The supplied power wires are long enough to do this. Unswitched power is required to allow charging for up to 2 hours after the ignition or head unit is switched off. Then, position the GW 500 so that there is clearance for the ashtray, gently place the fiber optic leads so they are not bent tightly or kinked (photo, lower right), and button everything back up.
So there it is. At this point I would proudly show the iPod illuminated and playing, with its ID3 Tag info (playlist name and song title, and elapsed time) displayed on the COMAND screen, and with the track number on the multifunction display. I might even show the Dension menu first page, with eight display options, on the COMAND display. But, alas, I can’t.
The user guide has a procedure for restarting the MOST bus after you change the position of the mode selector switch. The user guide also points out the location of a Reset button on the Aux/Mode Select unit, ansd says to use it during a troubleshooting process but provides no information on what it does. So far, however, using both has not gotten my system working.
As I said, not ready for prime time, mostly for the deficient installation guide, and also for the too-short copper wire connectors. If indeed the fiber optic connections must be rearranged in the trunk, information on which ones to move would be helpful; there is absolutely nothing addressed, and one can glean the need to do this only from the tiny and sketchy diagrams. Not having the unit work after nearly $500 spent on it is vexatious, to say the least.
I continue to work with the vendor, and with Rob. I cannot tell if my GW 500 is defective or if the bothersome need for switching of the fiber optic connections in the trunk is the problem. My unit came with firmware version 1.05, the latest, installed; but if you need to update, you can get it from the Dension support center at
Dension Support Center. I’ll keep you posted, and post more pics of the fiber optic connections when I get it working.