Installing Car Radio, Getting loud buzz (from unit itself)

The friendliest place on the web for anyone with an RV or an interest in RVing!
If you have answers, please help by responding to the unanswered posts.
See posts with no answers
B

babzog

Member
Joined
Nov 13, 2016
Posts
10
Hey folks, first post!

I've built an RV using a 36' gooseneck cargo trailer as a starting point.  Works quite nice for our needs as a winter race hauler and summertime rv.  Adding some final touches now.  Went to install a new Kenwood car audio deck in the garage area and, I'm getting a loud buzz from the unit when I plug in the connector. I also notice the overhead LED lights will brighten too when I plug in the unit.  The unit itself, does not turn on, unless, I turn on the batteries and turn off the power converter.

The power converter is an older unit (1979) that was in the trailer when I bought it and decided to continue using it so long as it worked.  The AC and DC circuits all seems to work, except for this.

Any idea what might be going on here?  Thanks for any help!
 
I cannot help but I will suggest that it could possibly be a bad or no ground for the radio.
 
I recorded the thing in action: http://www.youtube.com/watch?v=BLg8Tpjks50

If it were a ground, then, would it work st all with the power converter turned off? I have tried to isolate as much as possible, the various circuits but I have not found a solution (or cause) yet.

 
It sounds like the converter is producing dirty DC with no filtering. Not uncommon for an old unit, but it's causing a problem with modern electronics.
 
I wondered if it might be something like that.  Is this fixable, or am I looking at replacing it with a new unit?

Funny too, after I posted the video, I had noticed that, some of my LED lights are faintly buzzing.  I never made the association.
 
Your best bet would be to replace the converter with something newer - the Progressive Dynamics 9200 series is excellent.

You could also try running power and ground cables directly from the stereo to the battery - it may act as enough of a filter to let you get by with the converter you have.  Make sure the new ground cable is the only ground, meaning the car radio chassis is connected to it and not to another ground.

What kind of converter do you have now?  If it's an older Magnetek it's definitely due for replacement.  It's main output is not filtered and is meant to drive thing like fan motors and incadescent light bulbs that don't care about the waveform.
 
Many of the OLDER converters were like the Magnetek 6300, this is both a converter and a charger (TWO DIFFERENT THINGS in one box, not like the modern Converter/chargers (Both converter and charger are the same)

The 6300, and others like it, send raw rectified A/C to the loads (Lights, Water pump and such)  A 6335 can power up to 35 amps of lights and furnace and scuh.. There is a separate battery charger, also rectified AC, but only around 3 or 4 amps, this connects to the Battery.

When you unplug a relay inside the unit connects the two together so the battery can run the lights and such.

When you plug in however they separate.

NOW. Raw Rectified AC will cause either a 60hz or 120Hz buzz in your radio.  No question about it.
There is supposed to be a fuse or two, likely near the right side, (NOT the 30 amp fuses) that is hooked to the battery side and is there for running a radio, It may be moving the radio's power lead to this fuse (The first non-30 amp on the right) will fix it.

BUT. if there is a long wire run to the batteries, or if there is a bad connection, it won't.

Recommendation
Clean up all connections between converter and battery, Upgrade to a Progressive Dynamics 4645 (Replaces the electroncs you have now, but you use the same fuse/breaker panel so it's not that big a job.)
 
In this converter, iirc from a year ago, the branch circuits all come off the same lug. There is a battery wire (which I have not wired up to any circuits) coming out of the converter too. There is a fuse, blown when I got it, which I think was hooked up such that, the batteries were not feeding the converter, so it only delivered converted power... Or vice versa, I don't recall which now, but I did replace it when I cleaned it up and put it back in service.

When I wired the trailer, I sent one 10ga wire over to the road side to feed the furnace and I also sent over a 14ga to feed the radio, bathroom light, under cab light and tv antenna.

I have one 8ga wire run from the batteries up front heading to the converter (24' run, iirc; the power center is in the garage area, curb side, roughly halfway down the length of the trailer (36' total)). I used the steel trailer chassis as my ground (for the return from converter, lights, other loads, etc). Ran all the wire before having it spray foamed.

Primary 12vdc loads are: water pump, water heater ignition, furnace ignition and fan, radio, powered antenna, lpg detector, radio and a bunch of LED lights, inside and out. Garage area has led lights but primary lighting is 120vac flourescent. I added up the amps when sizing the wire for the battery supply and 8ga seemed about right (to me, at the time) for that run soas to minimize loss.

Batteries are two Rv type deep cycle (think they're shot now, they discharged last winter and now won't hold a charge) in parallel. Before that discharge, they would charge and run just fine (took a while to charge) while connected to the powertron.

I measured the powertron enclosure. I have the 12" width and plenty of height, but, the back to the mounting ears is only 6" (7" total depth, front to back). The website (specs for the 4645) says I need 7.25". Is there any way I will be able to make this fit? Cut out the back of the enclosure?  Also, the area where the breakers are now, is 5" wide. Would I be able to fit the fuse block in there?
 
If the converter is part of the power panel, are there two or 3 output wires
One black, one red and the optional one is blue?

Same if it's a stand alone though Id don't know the colors

Is there ar RELAY on the converter circuit board?

That will tell me all I kneed to know.. As I said, I think you are getting raw recrtified AC, not true CD which is why the buzz. the shot batteries are part of the problem.
 
There are three output wires, all the same colour (green), plus the battery wire (yellow). Yes, there is a relay inside as well.
 
Yup, that will be one of the raw rectified AC, and those will buzz unless the radio is connected to the battery lead and there are good batteries present or a battery simulator (ALso known as a hardening capacitor or condenser).

I'd upgrade the converter.. as I said. for intergrated power distribution/converter  Progressive industries 4600
For stand alone converters 9200.  Try to match the last two digits as close as you can Ie a 6335 woudl be replaced with an xx45 (I think that is the smallest they make)

The replacement will pay for itself after a year or two of NOT replacing the batteries.

But meanwhile, make sure the Radio is hooked to the BATTERY side of that relay, and the batteries are good.
If you use two I recommend six volt Golf Car in series.... More Bang for your Buck.
 
I appreciate the advice. What do you think of simply replacing the entire unit with something like the PD4135, currently on sale for $139 at bestconverter? I'd have to replace the breakers too As I don't think they come with it.
 
You might consider...

All in one distribution center, battery charger etc.
$129 on Amazon.com
The AC Distribution Panel is rated for 120-volt AC at 30 amps with up to five branch circuits. The DC section has six branch fuse holders, with a maximum rating up to 30 Amps each. All wire tail connections. Inteli-Power 4135 can recharge the battery to 90 percent in 3-6 hours using our patented Charge Wizard technology.
Progressive Dynamics PD4135KV Inteli-Power Converter with Built-in Charge Wizard:
  • Boost mode: 14.4V ? rapidly brings RV battery up to 90 percent of full charge
  • Normal mode: 13.6V
  • Storage mode: 13.2V
  • Equalization mode: 14.4V
 
babzog said:
I appreciate the advice. What do you think of simply replacing the entire unit with something like the PD4135, currently on sale for $139 at bestconverter? I'd have to replace the breakers too As I don't think they come with it.
Click to expand...

I think that would be a good plan.. PD uses Square D style breakers at least they did on my power panel,  and if I'm not mistaken they are likely identical to the breakers you have now.. So you may be able to reuse them.
 
I spoke to Randy today at bestconverter and he recommended the boondocker bpc4-60 replacement distribution center.  Little more $$ but he said it would have enough (more than) power for all the loads plus charging. Should have it in a few days.  Thanks for all your help and advice!
 
Installed the new converter on Sat and no more buzz!  Still have to wire up all the 12VDC but a quick test worked fine.  Much quieter too!  I appreciate the help!
 
Glad to hear it's working ... Did you ever figure out what model the old converter was?

(I do not design RV type converters but I do make my own "Power supplies" for some of my radios so I have a good idea of the possible issues)
 
You must log in or register to reply here.

Latest posts

Members online

Total: 1,255 (members: 32, guests: 1,223)

Forum statistics

Threads
131,997
Posts
1,388,837
Members
137,743
Latest member
Stark Fire
Back
Top Bottom