Hi Christian,
I just went through all dilemmas you have, too.
HMI-Modul (Hinter Tacho)
Bild 1/Nr.1 - Blauer Fakra-Stecker -> Funktion: GPS-Antenne (Ist das so richtig?) Don't know
Antennenverstärker (Hinter Display-Einheit)
Bild 2/Nr.2 - Grauer Fakra-Stecker -> Funktion: ???
Bild 2/Nr.3 - Pinker Fakra-Stecker -> Funktion: ???
Bild 2/Nr.4 - Blauer Fakra-Stecker -> Funktion: ???
OnStar-Modul (Hinter Display-Einheit)
Bild 2/Nr.5 - Brauner Fakra-Stecker -> Funktion: GPS-Antenne (Ist das so richtig?) Ja, GPS antenna
Bild 2/Nr.6 - Pinker Fakra-Stecker -> Funktion: Mobilfunk-Antenne (Ist das so richtig?) Ja, mobile antenna
Radio-Modul (hinter Handschuhfach)
Bild 3/Nr.7 - Schwarzer Fakra-Stecker -> Funktion: Radio-Antenne (Ist das so richtig?) FM/AM antenna 1
Bild 3/Nr.8 - Weißer Fakra-Stecker -> Funktion: ??? FM/AM antenna 2
Bild 3/Nr.9 - Grüner Fakra-Stecker -> Funktion: ??? DAB antenna
How to connect existing cables/connectors to Junsun Android head unit on the back plate:
- GPS: Nr.5 - Brauner Fakra-Stecker: use "Fakra Z Male to SMA Male cable", 0,1 to 0,15m length is enough (see picture).
- GSM: Nr.6 - Pinker Fakra-Stecker: use same cable as for GPS
- DIN antenna: join and connect both Nr.6 (Black) and Nr.7 (White) Fakra cables here, if possible. For better reception buy "Antenna Signal Booster Amplifier Amp Dual Fakra DIN Plug" (see picture)
Astra (and other newer cars) have antenna amplifiers that require power (+12V) over the coax antenna cable for better reception. Astra K Hatchback has them bellow rear windshield (behind plastic cover, one on the left and one on the right side.
You can take +12V from AMP blue wire at the back of Junsun headunit (this is meant to power external amplifier and is active only when headunit is on).
You will also need additional DIN female to DIN male coax cable (eg. 0,5m) to connect this Booster to Junsun.
Note: Junsun headunit does not provide 12V power over DIN antenna socket! I checked with the voltmeter. I works without power too, however reception is worse in some areas.
- DAB USM adapter: Nr.9 - Grüner Fakra-Stecker: You will need additional "Fakra Z Male to SMA Male cable" or "Fakra Z Male to MCX Male cable", 0,1 to 0,2m. It depends on your DAB adapter whether it has SMA or MCX socket (or something else...).
USB DAB adapter probably provides +5V to the antenna amplifier and can be enough to boost the DAB signal (at least in my case it is). If not you will need additional single "Antenna Signal Booster Amplifier" for DAB antenna.
- How to connect USB socket under armrest: Use Junsun enclosed 4 pin USB cable with blue plug (mini USB) and connect it to HMI Light Blue (not Blue!) mini USB socket. If you will not use HMI any more (or is it broken) buy "mini USB" to USB cable, at least 1,2m (better 1,5m). Put this cable bellow gear console from the drawer to the bottom of the armrest. Connect mini USB side bellow the car original USB socket. The other side put in the USB female side of the Junsun enclosed 4 pin USB cable.
Screenshot 2024-05-05 at 20.19.17.pngHigh Quality Universal Car Stereo FM AM Antenna Signal Booster Amplifier Amp Dual Fakra DIN Plug Converter Adapter.jpeg