Hi everyone, I purchased a brand new 2011 Range Rover Supercharged (full size) in April 2011. I got the Logic 7 Hi-Fi (1200 watt, 19 Speaker sound system) option installed with the vehicle. Since day one, I noticed if I turn the sound volume up to a high volume and turn multiple accessories on (or even every accessory off and only the heated windshield on), the sound starts clipping out. I then did some testing and learned that even when the volume is as low as about 70%-80%, the sound still clips out*. The dealership mechanic did some electrical draw tests with the truck started and learned that the sound is clipping out when the voltage drops below 12V; however, they are refusing to fix the problem because apparently other vehicles of the same year and sound system do the same thing. At first we thought it was a safety feature where the amp was clipping out to prevent damage but when the dealership trickle charged the battery to 100% charge, the sound did not clip out. If the truck even sat idle overnight after the trickle charge, the sound would clip out again the next day. I was told the vehicle is operating as designed and they will not do anything to try to fix it. I'm a person who loves sounds systems and I often listen to loud music, I think it's kind of ridiculous that this is considered to be normal and that Land Rover will do nothing. My 2009 Range Rover Supercharged had the upgraded sound system as well (different system with less speakers); however, the sound did not clip out on that even at 100% volume (I understand that that vehicle is quite different). My sound system guy I deal with suggested that the alternator may be too weak and a modified or aftermarket alternator should solve the problem (possibly paired with a deep cycle battery); however, then I run into issues with my warranties being void if something electrical related goes wrong. Customer relations basically told me that they won't do anything unless multiple complaints for the same problem come in. I understand that most people probably wouldn't even realize this problem exists under normal conditions. Does anyone have any input or suggestions on what I can do about this or what I can say to Land Rover? Does anyone have the same vehicle and can maybe see if they have the same problem?

*I calculated that value by counting how many steering wheel button clicks it takes to get from full volume down to zero volume, then started at full volume and click the button down until the clipping stopped and with simple math, calculated that value (I even verified the clipping wasn't only going from full volume downward but even from low volume and raising it to the clipping point).

Thanks for your time!

 

Your dealership should know that the electrical system operates above 12 volts. The voltage at the battery when running should be on the order of 13.8 - 14.4 volts. The alternator provides this voltage, and it drops slightly each time more load is added. But it should remain above 13.2 even with headlights, AC, radio, wipers, etc. all on. If your battery volts was 12, you would not be charging the battery, and on an extended trip the truck would quit running.

Now your alternator and electrical system may be fine, and simply the power circuit to and from this spine tingling stereo has some corrosion making a high resistance connection which makes a voltage drop to the stereo, but not anything else in the truck. Lets say we start with 14 volts at the battery, and you end up with 11 volts at the unit. 3 volts was dropped along the way. Let us assume that the unit draws 30 amps. Volts = amps X ohms, so 3 volt drop = 30 amps X 0.1 ohm. Point is, it don't take much at higher currents to make a big voltage drop. They could look for a poor connection or a poor ground connection, because the ground path is equally important. Before others post, I know the stereo could draw more or less, this is just an easy on the brain calculation.

Here's a post https://landroverforums.com/forum/ge...ter-pix-44317/ with a $20 tester you can plug in the cigar lighter, and monitor volts while you drive around. If volts are above 13, then radio problem is isolated to radio power wiring. If volts are below say 13.2, dealer has other problems with alternator and internal voltage regulator of same. Depending on what comes out of the OBDII port for this truck, you might also be able to monitor battery volts with a scanner, usually numbers are smaller and hard to read while driving and avoiding the riff raff.

 

Hey Savannah Buzz, thanks for your response.


As I understand, the voltage should remain above 12V at all times when the vehicle is started, am I correct? I'm assuming that there is a defect since the voltage is dropping below 12V while the truck is started; however, they keep telling that it is working "as designed" since the other trucks do it too. Any suggestions on what I can go back to the dealership with to say?

Head office customer relations basically told me that they won't do anything since it's "as designed" and will maintain that unless they get multiple complaints about the same thing.

 

Let's start with the basics.

1. A 12 volt battery is a series of six wet cells, each at 2.1 to 2.2 volts when charged up. So 12.6 - 13.2 volts. When truck is running, volts across battery should be 13.8 to 14.4. During the time the starter is turning the engine over, it draws almost 300 amps and the voltage will drop below 12 volts for that time, which is normal (just until engines starts and you release the key).

2. To charge it in a modern vehicle the alternator converts three phase AC power to DC, (direct current) with diodes, and feeds this through a voltage regulator to the vehicle. An alternator may put out say 150 amps power max, and maybe 5 - 10 amps of that goes back into the battery to charge it back up after cranking. The rest of the amps run everything from fuel pump, engine computer, lights, radio, GPS, seat warmers, security system, and on and on.

3. Once the alternator gets to the maximum output amps it can produce, the volts drop. If one of the diodes in the alternator is out, it will produce maybe 2/3 of the normal power. You can have a truck with a problem alternator that will crank, run all day, but at night, with lights, AC, and wipers on, the volts drop below that 13.2 and the battery starts to run the truck without being recharged. You can have a dead battery driving down the road, fuel pump quits, etc.

That tester will keep an eye on the volts, and you can see how various things in the truck impact the voltage (switch light on, AC off, etc.). You dealer tech could be chasing the radio, when that is just the canary in the coal mine, you could have something else causing the problem, and other items just have not gone crazy yet.

You can also have an auto parts store test your battery and electrical system in the truck for free.

 

What ever or where ever the problem is, it shouldn't be dropping under 12V and causing components (like my stereo) to clip out right? Do you guy think they can or should be able to get away with saying other trucks do it of the same year/model so it is "as designed" and brush me off??

So if i'm understanding correctly, if I keep my stereo turned up and the voltage is constantly at under 12V, I may eventually end up with a dead battery and possibly lose power to certain components?

One thing I should mention is, although the dealership keeps saying it's not related to the electrical system as I suggested, I keep getting the blind spot monitoring sensor blocked fault popping up intermittantly and also keep having signal loss intermittantly on my left and right side 360 degree cameras (I used to on the back camera but haven't since they replaced the camera but it has only been a couple weeks). They also replaced my air compressor a couple weeks ago because it had a problem but I haven't had the suspension message pop up since they replaced it. Do you think the blind spot and camera fault codes can be caused by the electrical system?

 

so please answer these questions, you will need a mutimeter to check the voltages and check them at the battery.
what is the battery voltage at idle with all accessories off.
What is the voltage at 1500 RPM acc off? If its less than 13.5 then you have a bad diode, and or a bad voltage regulator
Has the battery ever gone dead? You may need a new battery
How many miles are on your truck?
Has the battery ever been quick charged with a hi power charger? This can damage a diode and make the alternator charge less than 14.2

 

I'll have to get a multimeter and post the information once i get it.

My current battery has not gone dead before.

There is about 18,000km on my truck (not miles, kilometers).

The dealership has "trickle charged" the battery before. When they did so, the sound did not clip out for a while, even at 100% volume with ALL accessories on.. but it did start clipping out again after the truck sat over night.

 

Your vehicles electrical system is protected by a load management system.
One of it's funtions is to shut off non vital consumers so that other vital systems
(such as engine management, drive by wire etc) will operate properly.
The only things I can suggest, make sure the battery is charged and tested as good.
If failed, have it replaced, make sure the BMS (battery monitor system) is reset/calibrated
even if you dont replace the battery.
Then practice a little common sense and DON'T turn on ALL your electrical consumers while
trying to operate your premium audio system at full capacity, Especially while at idle!
It's just not gonna happen.

 

therealassmikeg, thanks for your input. I don't operate my vehicle with ALL my accessories on. As I mentioned before, the sound clips out at even about 70-80% volume with ALL accessories off and only the heated windshield on, or with the heated windshield off and a couple other accessories on. It's not only with blasted music with all accessories on.. by the way, this is not at idle, its the same while driving even at highway speeds

 

I might also suggest looking into the infotainment system and checking changing the auto volume and speed dependent volume settings and set them to a minimum.
I can't recommend officially at this time to try a gel type battery if your vehicle was built with a lead acid wet type battery (some of the 2012 vehicles are equipped with them though). I dont know if it will affect the BMS logic (even if you recalibrate it) and make your problem worse..It may be worth a try at your own risk
The heated windshield draws a lot of current to operate, typically this is a timed function and shuts off automatically after approx. 5 min anyway, at least this is the way Land Rover has done it for years and I cant see this changing.
The logic7 system 1200 watt system 12v 160 amp alternator.
converting watts to amps watts divided by volts=amps
1200 w /12v =120 amps
since we dont know if this is max or rms, lets just say that 80% is
1000 to 1200 watts or 120 amps. This doesn't leave much current for any other consumer to operate even at full ecm requested output from the alternator. This is when the load management kicks in and starts shutting things off. One system is the heated front screen. Even so your engine management, body controls, hvac, etc... need current to operate also. You are literally pushing the outer limits of your vehicle.
Here is an exerpt from the WSM description and operation of the Load Management System


LOAD MANAGEMENT SYSTEM
The load management system comprises software resident in the ECM module.
The purpose of load management is to protect the battery during abnormal usage of the vehicle. With the engine not running the system will request the systems on the Media Orientated System Transport (MOST) ring and the air suspension system to enter 'power save' mode. , A 'WARNING - LOW BATTERY' message will be displayed in the message center.
For additional information, refer to: Information and Message Center (413-08 Information and Message Center, Description and Operation).

With the engine running the system will modulate features such as seat and screen heating to prevent the battery voltage becoming critically low to the point where the vehicle becomes un-operational.

Hope this helps...