SOLVED - Generator draining batteries (it was a bad converter)

When we turn on the generator, it drains the batteries, instead of charging them. Had it to the dealer, who said they fixed the problem, but it still drains the batteries, and now dealer is out of business. 2013 RW 305 toyhauler.
 

cookie

Administrator
Staff member
Re: Onan/Cummings Generator drains the batteries

First I gotta say that I know little to nothing about generators. Maybe less.
I don't know if the generator charges the batteries or if the generator supplies 120 volts to the rig which will run the converter which in turn will charge the batteries.
Are you getting 120 to the coach?
The converter may be the problem by not charging. Have you checked to see if it is supplying 12 volts, actually 13+.
Do the batteries charge when plugged into shore power?
Have you checked the breakers at the generator?
Others with more knowledge will chime in with some help.

Peace
Dave
 

Lynn1130

Well-known member
Re: Onan/Cummings Generator drains the batteries

Call Heartland and see if they have a RV service center in your area that they have authorized. Also, You might want to contact Onan to see if they have a repair location in your area since Onan is the one who will be covering the warranty. If it is something other than the generator and it is still under warranty most reputable repair services will work with the company to get the repair done and covered. This may well be a problem with the converter OR something as simple as a loose wire at the buss. Have you checked those?
 

NWILSON

Kentucky Chapter Leaders - retired
Re: Onan/Cummings Generator drains the batteries

Have you tried resetting both breakers at the generator? You may have one tripped that's not powering the circuit with the converter/charger.
 

porthole

Retired
Re: Onan/Cummings Generator drains the batteries

Have you tried resetting both breakers at the generator? You may have one tripped that's not powering the circuit with the converter/charger.

Those breakers, when you look for them, will be on the genset itself.

Looking at the genny, the front cover comes off. Along the top, look for the seam, grab it and rotate the cover forward. You will see the two 30 amp breakers there on your left, genny's right.
 

danemayer

Well-known member
Re: Onan/Cummings Generator drains the batteries

Hi jacknmolly,

The on-board Onan generator should only use 12V when starting. Once running, it supplies 110V through an automatic transfer switch just like plugging into shore power. The Power Converter changes 110V AC into 12V DC to charge the battery and supply 12V power to the fuse box. The Power Converter doesn't know whether you're on shore power or on generator power. It operates the same on either power source.

If your battery is not getting charged when the generator is running, you may have something as simple as a tripped mini-breaker between the power converter and battery.

I've attached a picture of the manual-reset mini breaker. As the 2nd picture shows, it's in a row of mini-breakers near the battery.

Here's a link to our owner-written 12V Block Diagram and Diagnostic Guide. It explains the problem more fully and has drawings of the 12V system along with a diagnostic flowchart if it's not a problem with the breaker.
 

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wdk450

Well-known member
Re: Onan/Cummings Generator drains the batteries

Why don't we start with seeing if the convertor/charger is producing charging voltage and if that voltage is getting to the battery, irrespective of AC power source. This could eliminate a lot of stuff quickly. With your rig unplugged from shore power, Generator NOT running, connect a DC voltmeter across your battery. Note this voltage reading. Plug in your rig to shore power. If the converter/charger charging path is working, you should read a higher voltage on the voltmeter. If this doesn't happen, an easy next check is connecting the + probe of the voltmeter to the incoming wires (not the common bus bar) of the DC circuit breakers in the battery area. One of these breaker wires is from the converter/charger and should have a higher voltage reading than the battery reading. If this happens this tells you that that circuit breaker is not conducting and needs to be reset. If the higher voltage is still not found, you need to crawl in to where the converter itself is and check things out. You might want to try resetting your mains and each branch AC circuit breaker first and retest for correct DC voltage since this is easier than getting into the crawl space. If you go to your converter/charger, take your voltmeter with you, first check if the converter is indeed plugged in, check the outlet for power with your meter on AC volts, then finally check the output terminals for 12 volt (area) DC voltage.

If your rig passed the first test, and the converter/charger is indeed charging the battery on shore power, then you have an AC generator output or transfer switch problem. With your rig unplugged from shore power, and the generator running, do you have AC power to EVERY outlet you can test in the trailer, Does the Air conditioning run? These checks attempt to see if both phases of the generated 120 volts AC is getting to your electrical system. Places to check on the generated AC problem is the generator mounted circuit breakers, the generator area tie box, and the transfer switch (relay) which is usually near the converter/charger. The tie box is usually a 4 X 4 electrical box with wire nutted electrical connections between the generator and transfer switch. Many people have reported poor connections here. The transfer switch has inputs from shore power and the generator output AC power and a common output to the AC breaker box panel. The switch is normally connecting the shore power to the breaker box, but bringing the generator on-line will produce an input voltage that the transfer switch will sense and switch it to disconnect the shore power from the breaker box, and connecting the generator power to the breaker box. Since transfer switches have 2 sets of 3 contacts (Line 1, Line2, and Neutral) it could conceivably work O.K. on shore power, but not correctly on generator power if any of the contact points did not work right. So one failure mode of the transfer switch is that the trailer loses some of its power (one of the 2 Lines) in either shore power or generator power modes, not just a complete loss of power in either mode.

I hope this helps.
 
Re: Onan/Cummings Generator drains the batteries

Thank you all so much for your suggestions. This is our first RV and we are having trouble identifying locations of some of the parts you have suggested we check. I have tried to research diagrams or manuals that identify them in our specific model, but have not had any luck. We have tried some of the suggestions by other heartland owners as to the location of various components, but find that ours is apparently not the same. We tried to remove the wall in the "basement" as some have suggested, but ours has many items attached on the back side and it appears that it cannot be removed, so we feel stumped. Does anyone know where we can find specific diagrams for the RW 305? I called Heartland when new, and they said they dont produce them, but check the owners forum.
 

danemayer

Well-known member
Re: Onan/Cummings Generator drains the batteries

Before taking anything apart, locate the buss bar and mini-breakers near the battery. That's usually the problem and it may need only a press of the reset button.
 

porthole

Retired
Re: Onan/Cummings Generator drains the batteries

Before taking anything apart, locate the buss bar and mini-breakers near the battery. That's usually the problem and it may need only a press of the reset button.

And check the circuit breakers on the genny. I would start there and work your way towards the converter.
 

porthole

Retired
Re: Onan/Cummings Generator drains the batteries

Thank you all so much for your suggestions. This is our first RV and we are having trouble identifying locations of some of the parts you have suggested we check. I have tried to research diagrams or manuals that identify them in our specific model, but have not had any luck. We have tried some of the suggestions by other heartland owners as to the location of various components, but find that ours is apparently not the same. We tried to remove the wall in the "basement" as some have suggested, but ours has many items attached on the back side and it appears that it cannot be removed, so we feel stumped. Does anyone know where we can find specific diagrams for the RW 305? I called Heartland when new, and they said they dont produce them, but check the owners forum.


The RW305 is the same model as the Cyclone 3010, which we have, so as long as things haven't changed too much - here goes.

Standing on the door side looking in the basement. looking to the left (towards the rear) you should see a "pie plate", about 4-5" in diameter. This is an access plate that unscrews. Removing the center cap should give you access to the convertor 110 AC plug. Above the pie plate and nearby there should be a louvered vent.
Find those two items you you will now know where the convertor is located behind the wall.

Your rear wall may be in 3 sections. Wide piece in the center, 2/3 size of the center angled piece on the ODS (off door side) And a shorter section that is on the door side.

There should be 4 screws attaching the center wall and 4 screws attaching the angled ODS wall. But, that wall may have 2 screws along the inner vertical edge and 2 screws going perpendicular to the wall coming from the UDC (universal docking center)

There should not be anything attached to the wall from the factory preventing it from being taken down. If you have the yellow eureka central vac that protrudes though the wall, be advised it is not attached to it, only supported by it. Remove the cap and slide the wall off the vacuum.

The transfer switch you read so much about here is behind that center wall panel. The clunk it does when activating is a sign that it most likely is working.

But, before removing the walls - If you can hear the converter humming, odds are it is working.

Check those circuit breakers, the 110 AC breakers on the genny and in main panel
The 12 volt breakers in the front bay along the wall.

If they are all good and everything else seems to work in the trailer, check the fuses in the fuse panel next to the main AC circuit breaker panel.

Lastly, there are fuses on the converter itself, which you may need to remove that wall to get to.
You might be able to check - get to them by removing the louvered vent.

To get that section of wall down you have to remove the trim that goes across the opening of the basement and screws to the floor rafters of the bedroom. The trim, about 8's wide and covered with black carpet covers the chase where many wires are run.
 

wdk450

Well-known member
Re: Onan/Cummings Generator drains the batteries

I found a dealer/servicer with good reviews on RVServiceReviews.com in nearby Brea, Ca.:

Hitching Post Trailer Sales

  • 690 W Imperial Hwy
  • Brea, California 92821
  • (714) 529-8766

Here's one in Chino with good reviews: (sounds like an independent)
McBride's RV Service and Body Shop
13788 Oaks Avenue,Chino, CA 91710
909.627.7566

 
Re: Onan/Cummings Generator drains the batteries

Thank you all so much. I have since found out that the power converter was bad. Apparently is has been bad since the beginning, but since our dealer (now out of business) reported that they had already fixed it, Heartland agreed to cover the cost of replacing it, and our power problem is now resolved. Additionally, we found out we were trying to remove the wrong wall in the basement. We tried to remove the one that faces the pin near the generator, but found out we should have been trying to remove the one that is near the cabin of the unit.

We really appreciate the names of the dealers you found in our area. I will definately contact them as the only suggestion from Heartland is a 75 mile drive from our house, and the suggestions you listed are MUCH closer. Thank you all for being so helpful.
 
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