Advice

Cands

Member
I've got a R345 Oakmont that I purchased in April. Since that time, I've noticed in the quiet that there's a constant hum coming from around the fuse box at the stairwell. It's like a sound you might hear from a ballast of a fluorescent light that never quits. Everything works, but it just always hums. Just wondering, is this normal or is this a warranty visit?
 

danemayer

Well-known member
It's probably the Power Converter that converts 120V AC to 12V DC. Try turning circuit breakers off one at a time to see what makes the noise go away.

If you have a battery cutoff switch, and turn that off while testing circuit breakers, when you turn off the correct breaker, your interior lights will go out.
 

Cands

Member
Ok, I give up, where's the magucal battery cut off switch? Also, what's the downside to turning it off. I will never run this thing on a battery.

- - - Updated - - -

What about the converter?
 

danemayer

Well-known member
IF you have a battery cutoff switch (not all RVs come with one, but if not, it's a good addition), it'll be close to the battery. If you trace the heavy wire from the positive terminal of the battery, you'll typically find it within 18".

If you are always plugged into shore power, and remove/disconnect/bypass the battery, here's what will happen.

1. Over time the battery will lose its charge.
2. Some high current devices like landing gear or leveling, or stabilizers may not operate correctly without a good charge on the battery.
3. If shore power is interrupted, your entire coach will go dark without a battery.
4. While towing, if the battery is depleted or disconnected, the trailer brakes will not work in an emergency where the trailer comes off the hitch.

When I suggested switching the battery off while testing, that's just to make it obvious when you cut power to the Power Converter.
 

Cands

Member
Ok. Good response. So, if the hum stops then the converter is bad? The question is, do I roll the unit back to the dealer for work OR is this what everyone has to live with it?
 

danemayer

Well-known member
There's hum and there's HUM. If you can only hear it when it's quiet inside, that might not be a problem. Also, there's a fan in the converter. You might be hearing that. So far it's all subjective.

If you think it's too loud, to get a more objective view, one approach might be to download a sound level app for your smart phone and take a reading. Then talk to your dealer and maybe take readings on a similar coach at a dealership. I would say that a 6 dBM difference would be justification to request a replacement unit from Heartland. They're not hard to self-install if you want to avoid towing to the dealer and dropping the unit off for however long the dealer might take.
 

JohnDar

Prolifically Gabby Member
When the factory installs the converter, they just stick it wherever and it's not secured to anything. Could be it's just off kilter a little or touching some framing and you're hearing it vibrate when it's operating normally. And the cooling fan in it does not run constantly, only when it needs to. Locate it, move it some, and/or screw it down. Make sure it's got enough clean free space to ventilate itself. Mine was in a pile of dust/debris, with the fan pointing towards a wall. And directly under the black tank flush anti-siphon valve which broke and sent a flood down where it used to be. I had already relocated it out of there to a safe, accessible spot.

Most likely you don't have a battery cut-off switch unless you installed one (I did). The disconnect is to remove the cables from the battery, in that case.
 
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