[francisb2]

My base stereo (2008 T1 - no nav) screen died so I decided to upgrade to a new unit (pioneer DMH-220EX). First time I've done any ICE work and I can't find the answers online so sorry for the noob questions!

First question; which antenna plug do I hook the antenna adapter to; the white or tan/gold one? There's no noticeable difference in FM reception between the two
Second question; on the other end of the antenna adapter there's a blue wire and clip; what's that and what does it clip too/in?


Lastly; I wired the red to red cable (switched/acc 12V+) and yellow to yellow (constant 12V+) and noticed the unit came on right away despite no key in ignition. (on the plus side it worked great except for the bluetooth didn't work because I hadn't grounded the parking brake?!?!) I started the car and turned it off and removed the key but the head unit stayed on... so I figured I didn't need the constant 12V yellow, just the switched red to turn it on and off with the ignition, so I cut the yellow wire and now I get nothing. Clearly I need both. Is there some quirk with the Touareg that the red/ACC stays on for a period even after the key is removed? Should I hook up the red cable to a different accessory 12V+ instead of the old stereo one?

Thanks in advance for any help...

Francis

 

[volkswagens-for-life]

@Troystg knows a thing or two about stereos in these

 

[Troystg]

I am familiar with the T3's audio system..

However there are several things in the post I can help with but I need to get to a PC so I can reread and write at the same time.

Sent from my Pixel 4a (5G) using Tapatalk

 

[francisb2]

seem to have lost the picture I took of the antenna adapter so just to be clear this is the blue wire I'm not sure what, if anything, to do with...

and these are my choice of antenna to hook up to...

many thanks

 

[Troystg]

First question; which antenna plug do I hook the antenna adapter to; the white or tan/gold one? Sorry can't help on that one.


Second question; on the other end of the antenna adapter there's a blue wire and clip; what's that and what does it clip too/in? Blue wire is SWITCHED +12v from radio. Usually the radio has an "antenna out" or an "AMP out". That blue wire powers the FM signal booster on that adapter. It usually grounds through the antenna cable shield. If the "clip" you are referring to is at the end of the blue wire, it is there to plug into the wiring harness connector. You may have to change it to whatever your radio has.


Lastly; I wired the red to red cable (switched/acc 12V+) and yellow to yellow (constant 12V+) and noticed the unit came on right away despite no key in ignition. Did you measure and see if the voltage was as expected ( switched and constant?)

(on the plus side it worked great except for the bluetooth didn't work because I hadn't grounded the parking brake?!?!) Parking brake is usually for ViM not Bluetooth.

I started the car and turned it off and removed the key but the head unit stayed on... so I figured I didn't need the constant 12V yellow, just the switched red to turn it on and off with the ignition, so I cut the yellow wire and now I get nothing. Clearly I need both. Absolutely need constant hot (industry standard is Yellow, NOT automotive standard!)


Is there some quirk with the Touareg that the red/ACC stays on for a period even after the key is removed? Yes the Touaregs power up an down electronics separately from the ignition. When you press the remote or open the door various "systems" wake up...



Should I hook up the red cable to a different accessory 12V+ instead of the old stereo one? The OEM radio uses CAN-Bus to turn on and off... You should have a CAN-Bus adapter or compatible radio..

 

[francisb2]

Troy thanks for the reply. You're right the antenna ''clip'' is in fact a female terminal for the wiring harness plug (doh!) and I think is meant to go to a line on the head unit which says it's the "external amp control signal" but which I've read online can also act as power for the antenna booster.

So I'm all up and running now, thank you! Except the unit doesn't power on and off with the ignition/acc. I checked the voltage on the Tregs yellow (constant) and red (acc/switched) wires and they are both 12V+ constant. So it seems I need a connection to the canbus that acts as a relay to switch the red voltage on and off with the ignition OR I hook the red wire up to a 12V source that is actually switched on and off with the ignition and take the ''on/off signal'' from there.

Anyone have any suggestions for a suitable switched 12V source somewhere near the head unit that does switch on and off with ignition or acc?

Many thanks so far.

 

[Troystg]

You can either get a can-bus interface or just tap a fuse / cigarette lighter for switched power.

The fuse option will tie the radio to the ignition so no radio with the key out.

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[francisb2]

Hooked the switched line (red) up to the center console power outlets/cigarette lighters and now it turns on and off with the ignition key as it should without a canbus adapter... Happy days!

I wired the antenna power to the head units external amp control which supplies it with 12V whilst the switched line is on (not while the unit is on). The last bit is important; if you switch the head unit off the antenna booster continues to draw power while the switched line is hot, so if anyone is tempted just to wire it up to the Treg's constant red and yellow 12V+ and simply turn the unit on and off when you want, then the antenna booster will always draw power even with the ignition off and the head unit turned off... obviously switching the red line with the power outlets solves this.

Pioneer units need the parking/e brake line held to ground to allow bluetooth setup functionality.

Many thanks Troy!

I think it looks pretty good for such a cheap unit, the sound is perfectly fine with no external amp and the phone is crystal clear. The supplied USB extension fitted easily in the tray below too. Treg's good for another 13 years now

 

[volkswagens-for-life]

Looks real nice

 

[Troystg]

It does look good..

You have to have the parking brake on to setup / pair Bluetooth?!?!?!?!? That is silly... But I guess that is the only way an aftermarket unit can prevent driving and configuring at the same time since they are not integrated into the speedometer or Nav system.

 

[francisb2]

Thanks all. One last comment for anyone else doing anything similar; I chose the gold/tan antenna to hook up to but 3 ft out my drive it was apparent FM reception was horrible. Works great on the white one though so I guess the gold is AM for anyone living in 1970 and white is FM!

 

[francisb2]

You have to have the parking brake on to setup / pair Bluetooth?!?!?!?!? That is silly... But I guess that is the only way an aftermarket unit can prevent driving and configuring at the same time since they are not integrated into the speedometer or Nav system.

Exactly but I hardly see it as the responsibility of aftermarket stereo equipment manufacturers to stop drivers being muppets! In fact in solving the issue I discovered that the latest Pioneer units require the hand/e brake be released then reapplied to prevent simply bypassing the lockout! What a PITA!

 

[Troystg]

Thanks all. One last comment for anyone else doing anything similar; I chose the gold/tan antenna to hook up to but 3 ft out my drive it was apparent FM reception was horrible. Works great on the white one though so I guess the gold is AM for anyone living in 1970 and white is FM!

Could gold be gps or old cellular?

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