Hum in Radio Speakers 2004 Journey 39K

[doorguy-WO]

I have an 04 Journey 39K and the radio has a humming noise in the speakers. The radio selection switch on the right side of the dash at the top is labeled RADIO POWER with two positions, on the left is AUX and the right MAIN.

Lately it has developed a humming noise in the speakers regardless of which position it is in. At first, the humming noise was on the AUX side only, but now it hums in both positions. I checked with WGBO parts and the switch is no longer available. Has anyone had this issue and found a solution? About 3 years ago I replaced the radio with a Jensen stereo unit and it has been working fine up till recently. I still get the radio reception but with the annoying hum.

 

[Bnystrom]

By all means check the connections at the switch, but it's not very likely to be the problem.

Humming is often caused by a bad ground. Check the speaker connections and the ground lead from the head unit to the dash.

Another common cause is RFI from other devices. Have you done any other electrical work lately, specifically installing anything with a motor?

In an '04, if the speakers are original, they may be degraded. The foam surrounds on woofers can deteriorate, allowing the cone to flop around and the voice coil to rub the magnet. If they sound at all raspy, this is likely the cause.

 

[doorguy-WO]

Bynstrom, thank you! I will check all those speaker connections and grounds. I have not installed any other devices that could contribute to this issue. I'll let you know what I discover.

 

[Morich]

The battery choice is not likely to be a cause.
The function is to change which battery supply is used coach or chassis. When driving, the choice is pretty meaningless as the two are connected together, likely through a "mode solenoid" in your age group.
The small use of it that shows to me is if you are prone to listening to the radio for long periods while camped. If you leave it in the one using the chassis/ start battery, it is prone to running that battery down while the engine is not running!
So they give the option to switch the radio power over to the coach batteries to avoid dead start battery when you want to leave!
My first thought for hum is electrical interference of some sort. Bad speakers can be a cause but I don't think of that as being a hum as much as a "different" sound quality.
Ears are not the best for fine tuning things, so it can be hard to spot. Way back when getting out of the military and going to work in communications, I found I had lost certain frequency ranges. One was vital for testing but I also found the test gear was far better anyway and nobody important ever found out about my "disability"!
One thing that can easily change things is whether the engine is running or not, fans, or other motors are prone to hum. Tube lights and ballasts are frequent problems to consider.
But it may also be something as simple and hard to find as a wire has shifted so that it now lays close along another wire to get noise induced into the sound.
Tough one!

 

[Morich]

One of the things which can make this really hard to find is how random it can seem to be. Some reasons for why I feel it is not as likely to be battery power problems is the way DC power works. It is a pretty steady level and we often call it 12V, even though it does go higher and lower at different times.
So if we are speaking of 12VDC power, it tends to stay pretty constant and not as likely to cause hum, which is a changing level .
That can lead me to think of different level that are constantly changing. And if it is a steady hum, I tend to begin to look at power that is changing at a steady rate, over and over many times.
One of the big common things to do this is 110AC! It changes all the times and we call it 60 cycle or AC hum!
If old enough to have met the pops from having a problem with ignition points on older cars, you may remember getting a problem on the radios of the day where the pop noise was in time with the engine RPM? There was a capacitor that was meant to smooth out that hum and it was not uncommon to have to change it to quiet the radio! I think that problem has totally gone away but then we also have lots of other things that can cause small voltages to be created (induced?) in wire nearby.

One of the problems with finding the problem is just the simple number of things that can cause a hum. FM radio is less prone to the problem but if you use AM, you may still occasionally run across an area where you drive by some place and get a big burst of HUMM or other noise.
There are noise canceling coils and small parts to put around different wiring to see if it helps but that can be a real drag when you can't really tell where it needs to be without just trying it!
As a giggle to see what AI might give us on the latest ideas, I ran the question by and got this group that could take a lifetime to sort and try them all!

Some ideas might be possible but several are way out of what I consider doing!
But this is not something I do much since there have been so many changes.
That might make it a question to take the RV by a radio shop that likely has far more current info?
Magic in a bottle or much better training/experience?

 

[RayIN]

A bad capacitor can cause a hum, a failing florescent light fixture ballast can cause radio interference/hum too, if both are on the same circuit.
Yes radios have tiny ceramic capacitors.

 

[dnrainey]

First, is it only on radio reception that the hum occurs? I had a similar problem with the replacement radio I had installed in my 03 Journey. After about a couple of years it developed a high pitched hum, however it was present whether listening to the radio or CD, etc. It turned out to be the radio itself causing the noise so I replaced it with another unit. If everything else is turned off and neither your engine nor generator are running then I would suspect the radio or a poor ground at the radio. I know that the diesel engines shouldn't cause interference anyway since they have no ignition system like a gas engine. I had to just take a chance and buy another radio and hook it up to see that the sound went away. Also, if your Journey has the same surround sound system as mine, there is a separate amplifier/equalizer that is connected between the radio unit and the speakers. To check that for that noise, you would have to connect your radio directly to some test speakers to see if it goes away.

 

[Kickenrock]

In my 2005 Itasca Suncruiser when the inverter is powered on it causes a hum in my speakers. If your Journey has an inverter in the front upper cabinet which is powered on, try turning it off to see if the hum stops.