Electrical Issue- Bad Converter?

You should have more than 12 volts going to batteries

Doubt it is converter as it works when genset is running or plugged into shore power.
Could be a bad connection between the batteries and the 12 volt DC distribution panel.
Check converter output. It should be around 13 volts DC.
Check at batteries for close to the same voltage. Use a different ground connection as the battery to frame connection could be issue.
If voltage is not close check in 12 volt DC power distribution panel to isure 13 plus converter power is there on fuse going to battery.
Start following voltage drop between battery and 12 volt DC power distribution panel on both ground and positive conductors.

Rog1010 wrote:
Hello-

I have 2006 Weekend Warrior with the following electrical problems while on 12V-

1. Lights are dim and when other lights are turned on, lights go out for brief second and come back on.
2. Radio will be playing and a light is switched on, radio will power off and back on.
3. The battery panel shows "weak" regardless of the length of charge.

When plugged into shore power or generator running, everything works great.

Generator starts on battery power without hesitation.

I have put two new batteries in and have 12v from batteries to the converter.

Does this sound like a converter issue, a loose connection somewhere or something else.

If converter, could someone tell me the best way to check if bad?

Thank you for your assistance. Roger

Had to replace my converter last week. Had similar symptoms you described. The "weak" battery condition on the panel was showing that the batteries were not being charged. My refrigerator showing "error" with the temperature going up and trying to switch to propane plus the dim lights were the first signs. The RV technican checked the volts on the battery and then checked the current from the convertor to the battery and determined that the batteries were not getting charged. He had a small battery charger he plugged into an outlet on the outside of the trailer and then connected it up to one battery----everything worked again with no issues. He left the battery charger on overnight because he did not have a convertor with him. Came the next day replaced the convertor then with a current meter he checked that the batteries were being charged. Problem solved:)

Great...Thanks for replies. What should the battery voltage be with no load?

It does sound like the battery is bad.
because of its state of charge, it's impossible to tell what voltage it should be.
Disconnect it and check the voltage. If it was 12 with the converter running and it's 10 or 11 volts disconnected, it's toast.
Dont keep it connected to the trailer or it may fry the converter.

Rog1010 wrote:
Great...Thanks for replies. What should the battery voltage be with no load?

A fully charged battery , with the charger OFF, should read at least 12.6- 12.8 volts. With the charger ON it should read at least 13.5 volts.

CONverters get weak over time. INverters fail. After 14 years I replaced my CONverter as it was weak....didn't want to be stranded on a trip. Bought a Parallax 4455.
In the past month, my INverter failed...and that controlled the front TV, 2 outlets and, strangely enough, both outlets in the bedroom.

Having never USED the INverter in all these years, I had it removed (and bypassed) by a RV tech who is a neighbor.

Remember that it does'nt take very long at all for lead acid batteries to weaken requiring a good long slow charge .
Also lead acid batteries that seem dead or actually are dead can more often than not be messaged back to life . With a battery taking no charge . leave it on the charger and and it will slowly take more and more current the longer it's charging of course to a point. Another way which IMO is better is to shock charge it with Your vehicles charging system using 2 pair of jumper cables . Charge for maybe 10 or 15 min then hook up an dc electric motor or headlight and drain down for 3 to 5 min then charge from car for maybe 30 min then drain for 10 or 12 min if it has that much in it. repeat this cycle 4 or so times increasing charge and drain times some each time and by now if battery is going to come back all the way You'll know because You can power things good batteries can , So go ahead and slow charge (2 amps) for 36-48 hours of course filling with "Distilled" water only and keeping full throughout this process

Moved from Forum Technical Support

1. You stated you put 2 new batteries in and still had the problem.

2. You also have no issues when on shore power or generator.

You most likely have a loose connection between the battery and the 12v power buss.

The generator starting power follows different wires(#2 cables) which goes directly to the gen starter. So it will start even when your monitor is telling you the battery is low. The tank/battery monitor is feed from the 12v power buss/fuse box.

The converter feeds the 12v buss through different wiring than the battery feeds the buss and everything works correctly when on external power. So it isn't bad.

Look for a loose connection between the battery and the fuse box.

There are also (usually) auto resetting circuit breakers between the battery and fuse box. One other item you may have is a high current battery disconnect switch that could be defective. Not all RVs have them.