Electrical Nightmare
I have a 2003 Monaco Dynasty motorhome with an electrical problem that has puzzled just about everyone I’ve spoken with about it. It all began more than two years ago when I started the generator and the engine to return to Canada. The inverter began to sound an alarm, which went on for about two minutes and then stopped. The inverter is a Xantrex 2000-watt model, and the remote control is a Trace RC 7 GS. As we traveled, this scenario went on every 15 minutes or so.
I contacted Xantrex by e-mail and described to them the situation with the error code charger fault. They answered back saying the inverter should be removed and sent to them for repair. So, I decided to do some checking around with different people as well as trying different tests. I found out that with the engine and gen set off, the inverter functions normally. I turned the external power off and on to simulate a power failure, and everything operated as it should. In further digging, I realized that if I disconnect the external power and then start the engine (with the gen set off), everything operates normally. However, if I turn on the generator while the engine is running, in about 30 seconds the annoying buzzer and the red error charger fault starts. So, I called an RV specialist and asked him to remove the inverter and ship it to the authorized repair shop in Orlando, Florida.
A week went by and the repair shop had put my inverter on a test bench for four days. Their verdict was nothing was wrong with the inverter! So, we reinstalled the inverter and gave it another try. No good; same problem.
The RV tech talked me into replacing the inverter with another brand. With all the headaches I’d been through with this thing, I made a spur-of-the-moment decision and agreed. But after thinking about the situation, and based on the answer we got from the repair shop, I figured that a new inverter was not going to resolve the current problem, so I decided to cancel the exchange and dig further. I replaced the two chassis batteries for the chassis, since they were 6 years old, and I started the engine, which resulted in the annoying buzzer and error charger fault. I then went outside and turned off the auxiliary power breaker. I went back inside the coach and noticed the inverter was inverting all the power with the lights and refrigerator all running okay. I turned off the engine and went outside. I turned the auxiliary power breaker back on and came back in the coach to watch the inverter. I heard the transfer switch come on, and after 30 seconds the inverter went on standby mode. To this date no one has been able to precisely diagnose this problem.
To sum it all up: when the engine and the generator are both operating, the inverter goes into alarm mode with an error code charger fault. When the engine is operating alone, the inverter runs normally. When the generator is operating alone, the inverter runs normally. I sure wish someone could give me a clue to help solve this issue.
Gilles St. Gelais, F355942, Naples, Florida
The following answer was provided by a representative of Magnum Energy Inc. I hope it helps. If not, you’ll need to find a technician who specializes in RV electric to assist you.
“This is a strange situation for sure, but it sounds as though the charging from the engine alternator and the charger in the inverter are fighting each other. When the inverter/charger is the only source charging the batteries from either shore or generator power, everything is okay, and the charger is able to regulate the charge voltage just fine. When the engine alternator is the only charge source, the inverter is also fine, because it is not trying to charge or regulate the battery voltage. If I remember correctly, the RV series charger fault is because the inverter is seeing the battery voltage too high above the set point in the inverter/charger, and it keeps reducing the DC current, but the battery voltage won’t stabilize. At some point, the inverter/charger shuts the charger off and shows a fault, because it can’t control the voltage.
“My guess is that when the engine alternator is charging the batteries and the inverter/charger is also charging from the generator, there is a battery voltage issue. The inverter/charger is probably (just a guess here) in float mode, and it is trying to keep the battery voltage at 13.4 to 13.5 volts, depending on the setting in the inverter remote. The engine alternator is usually charging at around 14.0 volts, which is higher than the float set point in the inverter. The inverter would normally ignore this higher voltage coming from the engine alternator unless the voltage is significantly higher. I would check the alternator output voltage and make sure it’s not too high. It should be around 14.0 to 14.2 volts, but I have seen many alternators set much higher. I think the Dynasty had a Leece-Neville alternator, and it may be adjustable.
“Also, there is a solenoid that connects the engine battery and house batteries together when the voltage is above 13.3 volts. I would bet that if you disconnect that solenoid and run the engine and generator at the same time, you won’t see the charger fault, because the inverter/charger won’t see the alternator voltage.”
Electric Gremlins
We have a 2003 Newmar Kountry Star motorhome built on a Freightliner chassis with a 330-horsepower Caterpillar engine. My problem happens after driving through a heavy rain. When I turn off the engine, all the buzzers and dash lights activate. One time I had to disconnect the battery to get the engine to shut off. The key had no effect. I have contacted Freightliner and Newmar, and both said they had never heard of this happening. We bought the coach new and have had the problem from the very beginning. When it’s dry, there’s no problem.
Thomas Driscoll, F258855, Boring, Oregon
Have you actually taken the coach to a shop and had a technician try to replicate the problem? It seems the ignition circuit is getting wet and causing it to malfunction, but you’ll have to find where the water is gaining access to the wiring. For that you’ll need a knowledgeable technician. Henderson’s Line-Up, Brake & RV Inc. in Grants Pass, Oregon, might be able to help you or point you in the right direction to remedy this problem.
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