Submariner Gold
Active Member
- Joined
- Jan 8, 2018
- Messages
- 198
- Reaction score
- 27
- Location
- Berkshire United Kingdom
- Country
- United Kingdom
- Dash Cam
- Vicovation MF3
I have recently really been put through the loop, regarding an intermitant, distorting and cutting out of Audio on my car.
It has the super dooper ... utterly overpriced Harman Kardon crap Upgrade.
There is a known problem that these Amplifiers blow out regularly. They do more than amplify sound, they are also a fiberoptic audio gateway, and an incorporated radio Tuner.
One of the known tell tales signs of HK Amp. Failure, is one loses the Radio Stations either the names or the frequencies.
Initially I didnt seem to lose the starion names, but after weeks of intermitant working, a few times the station names disappeared.
Today I got my repaired HK Amp back from the repairer .. fortunately no fatal water damage, just some blown output stage mosfets. Note they did not find any issues with the integral radio tuner element.
All good or so I thought. And to some extent still do.
CD works perfectly and so does the Radio. When the car is starionery on Ign. Pos 1. (Note my Dashcams are off in this position).
I went for a drive, and I thought I would check everything, ref recommending the repairer to others with faulty HK Amps!.
BBC Radio 2 sounded bad, so did Capital radio. I also couldn't find a lot of stations, OK we dont have great radio reception here, but prior to this the Mercedes radio worked almost perfectly.
I drove home, and still had terrible radio reception, I could hardly find any stations.
End prognoses:
The CD works perfectly all the time.
With the engine off, the Radio is crystal clear and has oodles of named stations.
Start the engine, and you get horrible interference, (not engine whine), but very weak reception noises, and it looses most of the station names, but you can see the frequencies, note the intefrerence is only on the Radio.
Note I had wired in a dual USB charger port, from the rear cigar lighter fuse for the 2 Dash-cams.
The odd thing, I remembered seeing on a dash cam forum, someone mentioned they had radio interference with a dash cam.
So, pretty despondent about my amplifier repair, thinking they hadn't repaired the Amplifier properly, in desperation I unplugged both dash cams USB power cables ...
Hey Ho perfect Radio sound!, good reception and loads of named stations, whether the car was stationery or driving!
So I tried it stationery, with the Cameras reconnected, with the engine off, Ign. Pos 1. (Note dashcams are connected but not powered) .. great reception! All stations, > 20 were visible.
Switch to Ign.2 and on come the Dashcams. And the interference starts and I start to get partial loss of stations! Then in a few seconds most, say 90% of the radio stations disappear!
I then Unplugged the Dashcams one by one;
when I unplugged the front Camera the interference reduces, with one disconnected, then I removed the other rear Dash-cam USB cable from the USB port, and Radio recovers perfectly, and all stations, circa 20+ all come back! no interference!
So I assume, the USB power charger circuitry is all fine; as everything works perfectly in the Mercedes as long as the dashcams are not powered!
Note one USB cable goes along the centre console and up the A Pillar and to the centre of the windscreen.
And the other goes across the rear parcel shelf and curves up quite near the rear windshield Ariel!
The S Class also has a radio antenna amplifier in the centre of roof at the rear, near the rear windscreen.
Q. I feel The repairer did repair the Amplifier and Tuner properly, and its all down to these dam dashcams!
Note the repairer didn’t find any fault with the Radio Tuner element, so I assume they left it alone. Would you agree this interference is all down to the dashcams and nothing to do with the Amplifier Repair?
I also noticed, that even with the Dashcams connected, and the engine on, i.e. Cameras are powered, I can see all the FM frequency numbers, so I assume the Tuner is tuning to the right frequency, but as I then get no station names; my assumption is that the interference from the Dashcams is so great, that the Tuner is unable to “lock onto a station” ..... is that logic valid?
Here is the real pig! I bluntly NEVER listen to the Radio. So I dont know whether the Dashcams actually caused interference to the Radio, before I had these Amplifier intermittant problems.
I was positive that my Amplifier problem was not like the usual fault ... re the issue of always loosing Station Names, but then later, I discovered that maybe 15% of the time, (that the Amplifier started to work), that I lost Radio station names.
I now suspect, this could well have been, that when I was testing it when it distorted, I naturally turned the radio on just to check if it had lost radio station names. and that only a few of the times I tested it did I actually start the engine (and this activated the Dashcams), which then showed a loss of station names.
Has anyone heard of dashcams causing serious radio reception problems? Particularly has anyone noticed it could degrade the radio reception, to a point that it lost the ability to tune into a Station? i.e. would not display the station name?
Is my logic right, that its unlikely the Amp repair could have effected the ability to reject radio reception Interference , especially as they found no fault with the radio tuner; so logically the repairer would not have touched the integrated tuner section?
As I never listen to the radio, this doesn't cause me any inconvenience regarding the dashcams.
I Just want to be sure the Amp was repaired properly, which I am 98% sure it was.
I dont think this interference could damage the amp if I don't listen to the radio and run the engine.
The rear cam installation position
It has the super dooper ... utterly overpriced Harman Kardon crap Upgrade.
There is a known problem that these Amplifiers blow out regularly. They do more than amplify sound, they are also a fiberoptic audio gateway, and an incorporated radio Tuner.
One of the known tell tales signs of HK Amp. Failure, is one loses the Radio Stations either the names or the frequencies.
Initially I didnt seem to lose the starion names, but after weeks of intermitant working, a few times the station names disappeared.
Today I got my repaired HK Amp back from the repairer .. fortunately no fatal water damage, just some blown output stage mosfets. Note they did not find any issues with the integral radio tuner element.
All good or so I thought. And to some extent still do.
CD works perfectly and so does the Radio. When the car is starionery on Ign. Pos 1. (Note my Dashcams are off in this position).
I went for a drive, and I thought I would check everything, ref recommending the repairer to others with faulty HK Amps!.
BBC Radio 2 sounded bad, so did Capital radio. I also couldn't find a lot of stations, OK we dont have great radio reception here, but prior to this the Mercedes radio worked almost perfectly.
I drove home, and still had terrible radio reception, I could hardly find any stations.
End prognoses:
The CD works perfectly all the time.
With the engine off, the Radio is crystal clear and has oodles of named stations.
Start the engine, and you get horrible interference, (not engine whine), but very weak reception noises, and it looses most of the station names, but you can see the frequencies, note the intefrerence is only on the Radio.
Note I had wired in a dual USB charger port, from the rear cigar lighter fuse for the 2 Dash-cams.
The odd thing, I remembered seeing on a dash cam forum, someone mentioned they had radio interference with a dash cam.
So, pretty despondent about my amplifier repair, thinking they hadn't repaired the Amplifier properly, in desperation I unplugged both dash cams USB power cables ...
Hey Ho perfect Radio sound!, good reception and loads of named stations, whether the car was stationery or driving!
So I tried it stationery, with the Cameras reconnected, with the engine off, Ign. Pos 1. (Note dashcams are connected but not powered) .. great reception! All stations, > 20 were visible.
Switch to Ign.2 and on come the Dashcams. And the interference starts and I start to get partial loss of stations! Then in a few seconds most, say 90% of the radio stations disappear!
I then Unplugged the Dashcams one by one;
when I unplugged the front Camera the interference reduces, with one disconnected, then I removed the other rear Dash-cam USB cable from the USB port, and Radio recovers perfectly, and all stations, circa 20+ all come back! no interference!
So I assume, the USB power charger circuitry is all fine; as everything works perfectly in the Mercedes as long as the dashcams are not powered!
Note one USB cable goes along the centre console and up the A Pillar and to the centre of the windscreen.
And the other goes across the rear parcel shelf and curves up quite near the rear windshield Ariel!
The S Class also has a radio antenna amplifier in the centre of roof at the rear, near the rear windscreen.
Q. I feel The repairer did repair the Amplifier and Tuner properly, and its all down to these dam dashcams!
Note the repairer didn’t find any fault with the Radio Tuner element, so I assume they left it alone. Would you agree this interference is all down to the dashcams and nothing to do with the Amplifier Repair?
I also noticed, that even with the Dashcams connected, and the engine on, i.e. Cameras are powered, I can see all the FM frequency numbers, so I assume the Tuner is tuning to the right frequency, but as I then get no station names; my assumption is that the interference from the Dashcams is so great, that the Tuner is unable to “lock onto a station” ..... is that logic valid?
Here is the real pig! I bluntly NEVER listen to the Radio. So I dont know whether the Dashcams actually caused interference to the Radio, before I had these Amplifier intermittant problems.
I was positive that my Amplifier problem was not like the usual fault ... re the issue of always loosing Station Names, but then later, I discovered that maybe 15% of the time, (that the Amplifier started to work), that I lost Radio station names.
I now suspect, this could well have been, that when I was testing it when it distorted, I naturally turned the radio on just to check if it had lost radio station names. and that only a few of the times I tested it did I actually start the engine (and this activated the Dashcams), which then showed a loss of station names.
Has anyone heard of dashcams causing serious radio reception problems? Particularly has anyone noticed it could degrade the radio reception, to a point that it lost the ability to tune into a Station? i.e. would not display the station name?
Is my logic right, that its unlikely the Amp repair could have effected the ability to reject radio reception Interference , especially as they found no fault with the radio tuner; so logically the repairer would not have touched the integrated tuner section?
As I never listen to the radio, this doesn't cause me any inconvenience regarding the dashcams.
I Just want to be sure the Amp was repaired properly, which I am 98% sure it was.
I dont think this interference could damage the amp if I don't listen to the radio and run the engine.
The rear cam installation position
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