My buzzing stereo is making me crazy

mmario · 09-24-2009, 09:25 AM

I have a car stereo with CD player...harness is labeled easy install. Ground..constant 12 volt...variable 12 volt...have a working hot and ground wire in the front of my 1966 International...when stereo is hooked up..terrible variable buzzing from speakers and system turns off when I turn any dome light on. What is going on?? A DVD player is hooked to the same hot and ground wire and works perfectly without any change when the dome lights are on.

Minno · 09-24-2009, 10:40 AM

Do you get the buzzing sound on both radio and CD functions? Do you have the stereo chassis grounded as well? Most of them have a nut and bolt on the backside that connects to chassis ground in addition to the wiring harness ground. If the buzzing is only on the radio, and the CD works fine, then I would look at the antenna hookup.

Chris

handn · 09-24-2009, 10:46 AM

Along with the ground, check contact with you speaker wires with each other and other live wires. Even if the wires are insulated, you speaker wires will pick up interference from each other or other live wires.

FordTruck · 09-24-2009, 11:08 AM

we have the same problem on our '08. It is at Jackson Center right now and the technician said there is some sort of suppressor they are going to install to cure the problem. When we get the trailer back, I'll update the thread with any specific info I get from them

**overlander64** · 09-24-2009, 11:32 AM

I had a similar problem with my '64 Overlander, and it disappeared when the original Univolt was replaced with a high quality modern converter/charger/maintainer. The problem was also worse prior to Univolt replacement if the house battery wasn't in top condition.

Kevin

**Stefrobrts** · 09-24-2009, 01:04 PM

I have the same problem in my caravel (the buzzing part). I'm going to check the things mentioned above. It's been driving me nuts when we're out, but we haven't used it enough this summer to look into fixing it.

I'm surprised about the system turning off when you turn lights on. That sounds like a power issue. Could it be switching off the 12v when you turn on a 110v light or something like that (just taking a stab at it).

mmario · 09-25-2009, 08:25 AM

Thanks to all who gave advice...actually both the stereo (cd player) and the dvd player buzz and squelch when any dome light is turned on. You can be listening to the stereo and when you flick on a dome light the stereo just buzzes....the dvd player will actually turn off.

kennethowens · 09-25-2009, 08:42 AM

put a capacitor across the power source....it should
catch the transient currents

Crusty · 09-25-2009, 08:47 AM

I had this problem too until I installed two new batteries and it magically went away. A good battery functions as a very effective electrical noise filter.

nick6930 · 09-25-2009, 09:22 AM

I had a similar problem with a truck years ago. I went to radio shack and bought a capacitor that was easy to hook up. I apologize that I can not rember the exact name. The cause is electrical interferance, that is why it happens when you turn the light on or off. Most easy way to go to a car stereo installation place or radio shack and tell them of the problem and they will give you the right part.

kennethowens · 09-25-2009, 12:32 PM

Run a new seperate ground wire to the frame....unhook the old ground.
Any loose connection can cause trouble.
A fan motor....because they have brushes in them.
Pull the fuse that feeds it...see what else is being supplied
by that fuse. Feed it with the source from a different fuse.
There are several "If - Then" things you may do to isolate the source of a problem.

mmario · 09-25-2009, 01:40 PM

Wow...what great advice...OK here are my questions...

A capacitor across the power source...? Where does this go? What ohm??
I tried to connect the ground directly to the chassis....didn't work or change anything
A new battery...I will try this...

nick6930 · 09-26-2009, 12:14 PM

I did a little searching and what I was trying to describe was an in-line noise filter such as this one XM Satellite Radio at MyRadioStore - Noise Filters & Amplifiers - PIE Omni Directional In-Line RCA Noise Filter EIS-ILNO I also found this link talking about the issue Saturday Mechanic: Curing Radio Noise - Popular Mechanics The filter seems to help illiminate the alternator whinning noise caused in a vehicle. I am not sure it can help with the trailer. All other info indicates issues with being grounded improperly or another ampliance improperly grounded causing the interference.

Clear as mud right?

Mikethefixit · 09-26-2009, 01:53 PM

The filter Capacitors are going bad in the Univolt . I also have the same problem. I am looking for a Univolt Schematic if anyone has one. If I can find the value of the caps , I am going to switch them out this winter.