SL/R230: where is 12v ignition source for after market Headunit and amps
07-12-2018, 04:28 PM
#1
Newbie
Thread Starter
where is 12v ignition source for after market Headunit and amps
ok i running through a standstill trying to install an aftermarket head unit and amps... as i have looked every for a wire harness for aftermarket radio for this car.. no wire harness to be found... because of the fiberoptic.. on the harness for the command center (oem headunit) plug there’s 2 orange fiberoptic wires which i left alone. i decide to butt connect these three where’s to the aftermarket headunit harness === the brown (-ground) , yellow n black [12v battery ) and blue n yellow ( ignition). the headunit powers on when turn on the car but when i turn the key off ... the headunit still stays on n my interior dome light decide to stay on too ... please advise what am i doing wrong ..
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lyntis (03-01-2021)
07-12-2018, 04:57 PM
#2
MBworld Guru
There is no switched 12v power for the factory radio. It is powered by a constant 12v circuit, and then it powers on and off via signals it reads from the CAN bus. The same goes for the illumination - CAN bus signals tell the factory radio when the headlights are switched on. When installing an aftermarket unit, you need to get switch 12v and illumination from "elsewhere". If you are going to install a "stalk" interface (to operate the radio with the steering wheel buttons), those usually include circuits for switched 12v and illumination that they decode from their interface to the CAN bus. if not, you can use tap into the cigarette lighter for switched 12v and the ashtray light for illumination.
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lyntis (03-01-2021),
OnePiece@aTime (04-20-2020)
07-12-2018, 09:51 PM
#3
Newbie
Thread Starter
There is no switched 12v power for the factory radio. It is powered by a constant 12v circuit, and then it powers on and off via signals it reads from the CAN bus. The same goes for the illumination - CAN bus signals tell the factory radio when the headlights are switched on. When installing an aftermarket unit, you need to get switch 12v and illumination from "elsewhere". If you are going to install a "stalk" interface (to operate the radio with the steering wheel buttons), those usually include circuits for switched 12v and illumination that they decode from their interface to the CAN bus. if not, you can use tap into the cigarette lighter for switched 12v and the ashtray light for illumination.
07-12-2018, 10:12 PM
#4
MBworld Guru
No problem removing the Bose amp. You will be "breaking" the fiber optic loop when you remove the factory radio and amp. The TeleAid (a.k.a. mBrace) system does use that, so if you wanted to keep it active, you need to get coupler to connect the "broken" fiber circuits at the radio and amp.
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vinhtrandinh (07-13-2018)
07-18-2018, 03:12 PM
#5
Newbie
Thread Starter
"Installing a 3rd Battery and Solenoid relay battery isolator"
No problem removing the Bose amp. You will be "breaking" the fiber optic loop when you remove the factory radio and amp. The TeleAid (a.k.a. mBrace) system does use that, so if you wanted to keep it active, you need to get coupler to connect the "broken" fiber circuits at the radio and amp.
If i want to install a 3rd battery and a solonoid relay battery isolator. Would it be a problem? please advise?
07-18-2018, 07:53 PM
#6
MBworld Guru
I wouldn't. The car's electrical system with the two-battery setup is already complex enough. Unless you putting in some sort of crazy multi-thousand-watt setup, you should be fine with the car's battery.
07-19-2018, 01:07 AM
#7
Senior Member
Worth noting, if you disconnect the Teleaid, it needs to be coded with STAR, or the car will look for it on every startup and when it does not find it, it'll illuminate an SRS light since the Teleaid is part of the SRS (attempts to make automated emergency call if airbags deploy or is involved in a roll over).
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07-19-2018, 12:20 PM
#9
Newbie
Thread Starter
Worth noting, if you disconnect the Teleaid, it needs to be coded with STAR, or the car will look for it on every startup and when it does not find it, it'll illuminate an SRS light since the Teleaid is part of the SRS (attempts to make automated emergency call if airbags deploy or is involved in a roll over).
07-19-2018, 12:26 PM
#10
Newbie
Thread Starter
07-19-2018, 11:19 PM
#11
MBworld Guru
Teleaid can be disabled (and thus no error messages displayed) using SDS. But like I said, if you don't go unplugging things, it should be fine. Just replacing the head unit and "breaking" the fiber optic ring won't generate Teleaid errors. The most common cause of Teleaid errors is actually the "emergency" antenna located int he read bumper. A minor rear-end traffic accident can break it and then you'll get errors.
