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7 Inch headunit power question.

15K views 77 replies 9 participants last post by  ckoralli27 
#1 ·
Recently bought a 7 inch unit a couple days and just tried to test out the pins with a multimeter but i'm not getting any results. I have ground on pin 12 and ACC on pin 22 but no go... I also tried IGN 1 on pin 33 but still no reading. I also tried with a spare battery i have laying around here but i'm not getting any power. Any help? I have included a picture of the pinout as well.
 

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#4 ·
Surprised too, with many of these new car radios, not only ground and 12V, need a secret code from the BCM before you can turn them on.
Been repairing car radios for many years, use to use vacuum tubes, but some manufacturers feel somebody would want to steal your radio, so added anti-thief.

And repairable they are not, all special purpose integrated circuits, strictly throwaway stuff and sure are asking a fortune for them.
 
#8 ·
That's how it is on elantra's that has it originally installed? I keep thinking It's one of the can bus connections... I went over the wiring schematics last night and see that there's a multimedia fuse that controls the radio. I don't have the multimedia can bus connected at this moment...I'm also gonna try to connect the chassis-can and body-can later to see if that does anything.
 
#7 ·
92 DeVille was the first car where the radio stayed turned on after you removed the key, shutting off the ignition, what the heck! Elantra is the same way, no key but push the stop button, radio keeps on playing, more like about five minutes. Can switch it off manually, but another way to switch it off is to open the drivers doors.

To this day, do not comprehend the logic behind this, but was an engineer and not a marketing guy. One push of the start button is like putting an old ignition switch in the accessory mode where you can listen for longer periods of time. But about every two minutes, radio beeps and get a start your engine so you won't discharge your battery.

Don't get this either, a 40's radio with a sigle ended speaker system, vibrator, and vacuum tubes, would pull about 8 amperes even with low volume on the radio. These new radios even with medium volume only pull about an ampere, with a 60 AH, battery should play for a couple of days. But only talking about 20 minutes or so, waiting for someone you want to pick up. Beep Beep, start your engine. Beep beep, start your engine. What a waste of gas!
 
#11 ·
I'm starting to suspect all these problems are related to CAN as well..it got me thinking, how does the door maintain power to roll down the window after you turn off the car? The moment you open the door it loses power. I think the CAN bus is the one responsible for it. The backup camera also has 2 CAN lines which I guess activates the video signal when you put it to reverse. I did look up the CAN schematics on hyundai-tech last night and I did see some lines for the radio. Probably deals with the power signal when the car turns off... I'm gonna check it again to see if there's one for doors. I wanna see if my hypothesis is correct. Looks like we really need connector C after all -_-
 
#19 ·
...The moment you open the door it loses power. I think the CAN bus is the one responsible for it. ...
That is normal operation. Radio stays on, and some accessories are available, after you turn off the vehicle, until you open the door. When you open the door, these are no longer available. So if you are concerned that this behavior is an error...it's not. It's the way it's supposed to behave.
 
#18 ·
Ignore the mts pin that's for bluelink on the rear view mirror. Yea I'm gonna test out connector C in the morning.. I found out where the CAN wires go from the radio. They go to a joint connector in the main harness but that's located up inside the dash. I traced the can bus wires all the way back to the bcm by checking the schematics. I'll tap the wires from there. Body-CAN and Chassis-CAN are the ones to focus on..Multimedia-CAN don't think we need to bother with that since it deals with the AMP. I'll post my findings later in the day.
 
#21 · (Edited)
little more info..The 5" does shut off after a couple of minutes or when the door is opened. It does not have connector c or even any of the wires in connector C. Makes me think nothing in C relates to the radio shutting off. The only other difference that I haven't mentioned earlier is pin 36 on plug A of the 5" stereo is camera equipment detect. This wire is not listed on any of the plugs for the 7". I was told by someone else in another thread that when the camera is detected the power warning no longer pops up..that thread is... post # 14
 
#22 ·
have you tried to connect the camera power line that feeds the camera to back up light through step down voltage transformer (12v to 6V) and ignore pin 6 on connector A so once the camera get power from back up light it going to send the video signal to pin 7 on 7inches screen ?? also did you find something new about radio keeps on after shut the car down and open the door ???
 
#23 ·
I've had no luck getting the camera to be detected by the 7" stereo. I know for sure the camera is wired correctly and I'm sure there is no need for 12v to 6v stepdown as both are Hyundai factory radios and cameras for both are the same. Because of unable to sort out the camera I just quit messing with it. I'll keep the stock till someone makes an install kit and the correct wiring adapters for the 5 inch stereo. Yeah no one makes the correct wiring adapter as of yet for the 2019 Elantra or the dash kit.
 
#24 ·
yes both of your camera and 7 inches screen are oem but remember the harness for the base model stereo has no terminal to power the camera as in the 7in screen harness which comes with 6v terminal to power the camera when the gear put on R and after camera gets the power is going to send the signal to pin 7 then the screen going to show the video ,,my idea is getting another power source for the camera to get the signal to activate the screen when you put the gear on R ,,, another idea is to check pin 12 on connector B on for base model to see if there is 6v power in it when you put the gear on R to power the camera because as i saw in wiring diagram for backup camera the power line of camera is mentioned as B+,,, i will try all probabilities next few days and i will post the updates
 
#27 ·
The factory camera is 6v.. no need for a stepdown unless you are using an aftermarket stereo. The 7" stereo does not detect camera with it wired correctly. It is wired correctly for sure I have the pinouts for both stereos. It just does not detect there is a camera connected. Also I have a friend who works at a customization shop. He has tried to get this working. It just will not work in my car. Makes no sense but that's just how it is...
 
#28 ·
The factory camera is 6v.. no need for a stepdown unless you are using an aftermarket stereo. The 7" stereo does not detect camera with it wired correctly. It is wired correctly for sure I have the pinouts for both stereos. It just does not detect there is a camera connected.
try to test you camera by connect it to another screen (any screen has AV input ) by feed it from your 6v pin on your harness it might be not working just to make sure nothing wrong with your camera and make sure that your harness is giving 6v first
 
#32 ·
Should only play for about ten minutes then switch itself off. Another rather old fashion way to switch off the radio is to do it manually, OMG!

More than likely one of the four door switches, namely the drivers door is not making contact when you close the door. And if you have anything plugged into your auxiliary 12 volt outlets, they will be left on too.

Kind of like the old fashion ignition switch, in off, well everything is off except the headlights. Walking in a store always heard license plate number so and so on the PA system, your headlamps are on. Ha, nobody memorized their plate number so the entire store exists.

Only was to switch on the headlamps in our Elantra's, least mine is with the engine running.
 
#33 · (Edited)
Guys i have awesome news! I managed to fix the battery discharge warning and power off problems today! Turns out Multimedia Can Bus has to be connected! I went again through the diagrams of the cluster and noticed multimedia can bus goes through it. I also noticed there's a alternator signal that passes through it as well. Also one other thing, the screen turns black when you reverse as well for the backup camera. You have 2 points to access MM-Can, the cluster itself or through the ODB-II port. The orange MM wire is orange on the port while the other mm cable is not exactly blue.. more like a greenish wiring. I know tc0566 was having problems with the camera. I attached some photos of it. Time to celebrate! :) I never bother with MM-CAN because i thought it wasn't important. well now i know you have to cover all bases when it comes to these things :)
 

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#34 ·
And where are these wires located in a 2019 which of the stereo plugs and what color wires.. using schematics like that doesn't really help when your going from different years. My car does not have the Canbus wires in C plug. The plug doesn't even exist. This is is why I said unless you have 2019 you can show me it works on it doesn't help me in any way. There are are high and low Canbus pins at 7 and 20 on B plug of the 5" stereo. Those are in the same pins and are connected in B plug of the 7" stereo. It does not solve the problem for the 2019.
 
#35 ·
Yea i see that theres no can bus for 5 inch here...what i did for mines was tap into the BCM for B and C Can Lines since my car doesnt have em on the original harness... So you tried already connecting MM can and still nothing? you want me to give you schematics for the radios for 2019?
 
#42 ·
Yea i see that theres no can bus for 5 inch here...what i did for mines was tap into the BCM for B and C Can Lines since my car doesnt have em on the original harness... So you tried already connecting MM can and still nothing? you want me to give you schematics for the radios for 2019?
[/QUOT
another thing ,,, could you please locate the MMcan ?? and where is connected on 7in monitor also on mono type stereo connector??
 
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