I replaced my old Alpine head unit today with the 143-BT Alpine head unit. Installation was plug and play since I already had a Modifry DCI and wiring harness. The only glitch is that the mute function doesn't work. The other dash functions work fine. I tried various settings on the head unit and did several searches on this forum. Is there a setting that I can change on the head unit to enable the mute function?

Thanks in advance.

 

I'd start here: Modifry's S2000 DCI Help

 

According to the installation diagram that head unit does not have a mute function. A true mute (zero volume) requires an "audio interrupt" wire on the head unit, which might be called ATT or identified as a cell phone wire on some head units. On Alpine it's pink with a black stripe and does not exist on the CDE-143.

However, the HU almost for sure has an attenuate function (which they probably call mute even though it's not) which will work if you change the switches on the DCI. On current DCIs that would be switch 1 but it might be different on older models. When testing, make sure you change the switch with POWER OFF, or turn power off after changing it. The DCI only reads that switch during the power-up cycle. If set correctly, the DCI will perform the same "mute" function you get when pressing the mute button on the front of the HU.

 

I suspect that your old headunit had a a hard-wired TEL/MUTE, while the new one doesn't. The DCI supports both
sending a mute command via the separate wire or via the regular remote command, but IIRC you need to change
a dipswitch setting on the DCI to send the mute command via the latter.

EDIT: while I was composing my response, Modifry posted the definitive answer.

 

Thanks for the help all. I figured the head unit didn't have a mute function. When I have some time I will try different dipswitch settings and post back.

 

Well, I changed the dip switches one at a time with the power off to the head unit, and I couldn't get the mute to work. I don't think it is supported by the head unit. I did take a couple of pictures that show the settings that worked with my old unit and seem to work best for this one as well. I also included one of the DCI (10 years old and still working great!). I believe the version # is 0.312. Thanks to Bob for supporting his quality products long after the sale. I'm going to leave the DCI exposed for a few more days in case anyone has some suggestions.

Again many thanks.

 

Ok, moving into pure conjecture here...
Alpine's specs list the headunit as "Remote Control Ready" and Alpine's remote RUE-4202 has a prominent "mute" button, I would think
the headunit does support a mute command.
Digging into Modifry's old website there are some old DCI instructions that show an 8-dipswitch DCI-2 (though not the wired one that you have)
in which switch 3 should be in the ON position to send a mute command via the dash control wire rather than the dedicated mute wire (5-6-7-8
should all be down for Alpine, as yours are). So best bet would be to turn #3 on, though it sounds like you've already tried that....

 

Yes, on your old DCI switch 3 down will send a mute command on the 3.5mm cable. However, I think it's possible that your HU does not have a mute function other than the software mute that occurs when you make a BT phone call. I say this because there is no mute button on the face of the HU, which Alpines used to always have when they had a "attenuate" mute function. Also I searched the owner's manual for the word "mute" and the only time it appears is when describing BT calling. Interestingly, the front face has a play/pause button, but Alpine remotes have never had one, and usually only those commands that appear on the hand-held remote will work via the wired remote input.

I took a look at Crutchfield's web site and it appears that Alpine is phasing out the mute function (you suck Alpine). Only one HU (HD149 $300) has a mute button on the front face, but it does NOT have the interrupt wire so it likely only lowers the volume instead of pausing. There were a couple models that still have the pink/black audio interrupt wire, UTE-62, and the 163 and 164 models. But they don't have a front face mute button. In all cases with the pink/blk wire you must go into the HU settings and turn on the mute function or else instead of pausing it will switch to the AUX input. That might work as a pause if you don't have anything plugged into AUX, but obviously not if you're using it.

 

Well I am very happy to report that turning on dipswitch #3 did attenuate the volume. If I am listening at a level of 15 the mute button takes it down to a 4 or 5 level. At that point it is soft enough to have a conservation. Although not a true mute, it is a big improvement over not working at all. Again many thanks to oth and Modifry.

 

I have this same HU with the Modifry DCI, pressing the mute button turns the volume down as well (but not full mute); FWIW, iirc, I didn't change the dip switches at all.