12V Ceiling lights dimming and brightening

[eblansfield]

We took our 2010 Sundance 5er out for the first trip of the year. Shortly after setting up at the campground, and hooking up to 30 amp service, the ceiling lights started to dim and brighten rapidly for a few second and then would stop. Maybe 20 or 30 minutes later, it would do again. Then it may be an hour or two before the lights would flicker once again. It even sounded like the heater blower was slowing down and speeding up with the dimming of the lights. At first I was afraid that the shore power at the campground was fluctuating. I switched to the other 30amp outlet in the box, but the fluctuations continued. We have used this spot many times over the past couple of years and never had an issue before. No one else around us was having an issue.

I figured since the 12v lights were having the issue, it may be the inverter. Has anyone else had this problem?

We just got home and unpacked. As soon as I can, I am going to sit in the camper for a while to see if it does while hook to shore power at the house.

Any help is appreciated.

Thanks

Earl

 

[wdk450]

Earl:
To see if the problem is the converter/charger, find its breaker on the AC circuit breaker panel and turn it OFF, while watching the 12 volt lights for a while. If the problem is now gone, it is probably from the converter/charger; If the problem still happens it is a bad connection somewhere in the 12 volt DC wiring. Check all battery connections and cables - if you are actively looking for the problem turn on every 12 volt device you can think of and FEEL the 12 volt DC wiring and connections for points of heat. Heat means you have a poor connection at that point.
You also might have an intermittently shorting cell in the battery - a DC voltmeter check across the battery should show you this with a load test - when the lights dim, the battery voltage would spike down with a bad battery and the converter/charger OFF.

 

[cookie]

Don't forget to check the connections at the neutral buss located near the battery.
It's the block with all the white wires going to it. Check the screws.

Peace
Dave

 

[eblansfield]

Thanks Dave and Bill. I just got back in the house and saw your post. So I will follow your instruction when I get back out to work on it.

While I was out in the camper, before I had a chance to hook my meter up, the lights flickered rapidly and I could hear a weird buzzing sound coming from the inverter area. Then it stopped. So I hooked up my meter to the 12v post in the fuze box and watched the voltage with when the inverter was off and waiting to see what happened. When the inverter kicks on, the voltage spikes to 14v and immediately drops and holds at 13.3v (the lights brighten). When the inverter turns off, I can watch the voltage drop rapidly down to about 12.25v and slowly down to about 12.1v within a two minute period (lights dim) before the converter kicks back on. If the inverter had not kicked back on, seems the like battery voltage would have continued to drop and at that rate, would probably be dead in a hour or so. Maybe a bad battery?

I waited for over an hour and I never got the rapid fluctuation and buzzing sound from the inveter while I had the meter hooked up. The buzzing almost sounded like a arcing sound so I shut the main 120v power switch off until I can check it out.

I have never looked at the inverter before and I think it is behind a panel in the basement. I can hear the fan running under the step leading up into the bedroom. The basement is still completely full of stuff from the trip and it is now raining. So I will look at it when I get a chance. I am sure I will be in touch and I appreciate the help.

 

[danemayer]

Hi Earl,

If you have the Progressive Dynamics PD9200 Power Converter, or something similar, it automatically changes output voltage to respond to the battery charge level. Here's a description:

The INTELI-POWER 9200 series converters have the Charge Wizard controlled charging module built in.
The Charge Wizard is a microprocessor-controlled device incorporated in Progressive Dynamics 9200 Series Inteli-
Power Converters. It constantly monitors the RV battery, and then automatically adjusts the converter output
voltage based on its charge status. The Charge Wizard has four (4) operating Modes (BOOST, NORMAL,
STORAGE and EQUALIZE). Each Mode is automatically selected by the Charge Wizard and ensures a fast yet
safe recharge for your RV battery.

It could be that there's a problem with the battery that's causing the power converter to cycle through modes.

Here's a link to the folder in the manuals section of the forum that contains the PD9200 and other converter information.

Here's a link to a 12V troubleshooting guide that you may find helpful.

 

[Rickhansen]

I figured since the 12v lights were having the issue, it may be the inverter.
Thanks
Earl

Hi Earl,
I assume you are talking about a converter, not an inverter. Not sure what converter you have in your coach, but I am familiar with the Progressive Dynamics 9200 Series. These converters are the to power your 12 vdc systems and maintain your coach batteries. They will switch their mode between 13.2 and 14.4 volts to properly charge and condition your batteries. This is often seen as brightening and dimming of your 12-volt lights. These converters also have a cooling fan on them, that will speed up as the heat increases because of load.

Since this is your first trip of the year, your batteries might be low on charge, or may have developed a bad cell over the winter. I'd check the voltage with a meter as the lights go up and down. If you see anything more than 15 volts, you probably have a more serious problem. You should also check your battery connections to make sure they are clean and tight. If the problem last more than a few hours, I would recommend that take your batteries in to be load tested.

Hope this helps,

 

[wdk450]

Earl:
It sounds like you are on the way to isolating the problem. Don't forget to check for loose 12 volt DC connections at the converter/charger.

BTW, we need to all speak the same language to make sure we are communicating effectively. The device that inputs 120 volts AC and outputs 12 volts DC is universally referred to as a "Converter" in RV lingo. I like the longer, but more accurate "converter-charger" which identifies its dual purpose, and varying voltage output stages, to rapidly and effectively charge the lead acid batteries while also providing current to the 12 volt DC devices in the RV. An "Inverter" in RV lingo is an electronic device that inputs 12 volts DC and outputs 120 volts A.C.

I just did a Google search for a good RV electrical power education site, and came up with a very good new one aimed at Class A owners, but mostly applicable to us towable owners, too. Just ignore the references to "Starting Batteries" and know that on-the-road battery charging for us comes through the tow vehicle connection cable. Here is the link:
http://www.rvcruzer.com/electrical/tutorial.php

 

[eblansfield]

Thanks all and I apologize for my misuse of the word inverter. It is a converter. I hate the number of issues I have had since we bought this unit new two years ago, but the bright side is that I learn something new with each problem I encounter.
I
looked in my paperwork that came with the RV but didn't see a manual on the converter that I have. My contact number for the converter inside my panel is for Progressive. I assume that is the maker. I will know more when I can get to it and take a look. I will digest the advice you have all given me and we where it leads. I appreciate it.

Earl

 

[wdk450]

Earl:
There are many manuals under the "Tools" tab at the top of each forum page - Follow the "Manuals", "Electrical", "Converters", "Progressive Dynamics" choices to get to the manual for the PD9200 series.
There are lots and lots of manuals on Heartland products, subsystems, and vendor components there.

The Progressive converters are not internally repairable - there are only 3 user-replaceable output (12 volt) fuses (in parallel) on the outside of the case. The case is riveted and has special head screws. The converters are expensive (about $240), but Progressive has a repair credit program if it is out of warranty. These are microprocessor-controlled, sophisticated, 4 stage, battery charging devices.

 

[eblansfield]

Thanks for the help and information. I had the battery tested and it tested good. The terminals are clean. So I tore the wall out of the basement of the rv and finally found the converter. I tightened all connections at the converter and at the battery and all along the neutral bus. I sat in the camper for a couple of hours to see if I still had the issue. I did not get the rapid brightness fluctuations as if we were losing power that I was having on our trip. However, the converter still turns on and off at about 5 minute incriments with 3 overhead lights, the heater, and the TV on. When the converter turns on, the lights brighten and the heater fan seems to speed up. The opposite happens when the converter turns off.

So, I am not sure if it is normal for the converter to cycle on an off about every 5 minutes. I don't remember that happening the whole first year we used the camper.

Of course, I forgot to check the brand and model of the converter while I had it apart. We have a weekend trip coming up in two weeks. We will see how it goes.

 

[RuralPastor]

Earl, the way you describe the converter operating makes me believe it is functioning properly. However, it is entirely possible for a battery to check out "good" at the local shop because they are testing for CCA (cold cranking amps) rather than deep cycle capacity. Your symptoms are consistent with a battery that is short cycling (not holding output voltage within the constant range for an acceptable time). A deep cycle battery is designed to hold the voltage at the threshold longer than a starting battery. You will get by for a while with this--maybe even this year--but I wouldn't want a $100 battery stressing my $300 converter. I'm guessing you've checked the electrolyte level in your battery as well.

 

[Rickhansen]

The convertor should never "turn off". It should only switch it's mode, and definitely not on anything as short as a five minute cycle. Did you verify the voltages through the operating modes with a meter? I do recall reading a thread a while back, that someone had a converter that was mounted too close to the utility wall, obstructing airflow from the fan and causing an overheating condition. You can probably find it with the search utility.

The fan is controlled thermostatically. The converter should be thermally protected - maybe it is shutting itself down due to a temperature problem?

If the converter "turns off" it would be evident by only the battery voltage (12.2 volts or less) present on the DC bus. Did you see that occurring with your meter?

 

[wdk450]

Earl:
As Rick said the convertor should never turn "OFF", it should just shift charging states and associated voltage output levels. I believe that switching levels at 5 minute intervals definitely indicates a problem. As you will see on the link following, the charge states should change in hours, and tens of hours, not minutes.
Call Progressive. Have your model and serial #, if possible.

http://www.progressivedyn.com/prod_details/charge_wizard.html

 

[brianharrison]

Lots has been said however there may be a couple of issues going on at once. I am not convinved the converter is operating as designed due to Earl's original post describing the voltage surge and then drop to less than 12.1V. For non-intelligent chargers (what I think Earl has in his coach) - it should be 13.6V constant when plugged it. With intelligent chargers the voltage is 14.4, 13.6 or 13.2, depending on state of charge the converter is operating at.

Something is driving voltage down in a short period time (less than 5 min from originl post)- loose connections have been removed from the equation because the Earl tightened all the usual suspect spots. The battery has been load tested which should indicated a bad cell or short (I think).

Earl the Cycyling you are hearing is probably the thermal fan coming on in the converter - there should be an internal temp sensor which turns on/off the converter fan to help it with cooling.

What else could drive high amp draw? pulling down voltage? Short in appliance? .

I will be following the thread.

 

[eblansfield]

Thanks Bill and Rick,

I put a new battery in and still have the same issue. So that isn't the problem.

I posted early in the blog that I hooked up my meter to the 12v post at the fuze box and watched the voltage when the inverter switched modes to see what happened. When the inverter switches to charge mode (i am guessing), the voltage spikes to 14v and immediately drops and holds at 13.3v (the lights brighten) for about 3 to 4 minutes. The the inverter switches modes again (lights dim) and I can watch the voltage drop rapidly down to about 12.25v and slowly down to about 12v within a two to three minute period. Once the voltage hits about 12v, the converter switches back to charge mode and we start all over again. If the inverter had not kicked back on, seems the like battery voltage would have continued to drop and at that rate, would probably be dead in a hour or so.

I will have to take the basement wall out again to see what the make and model of the converter is. Hopefully, I will get to that this evening.

 

[eblansfield]

Would it work if I watched the meter as I pulled each fuze one at a time see if the drop in voltage stops (or slows dramatically) to isolate where the drain is coming from?

 

[danemayer]

Would it work if I watched the meter as I pulled each fuze one at a time see if the drop in voltage stops (or slows dramatically) to isolate where the drain is coming from?

That might help. If nothing changes, try isolating the battery and the buss bar as well. If you have a battery cutoff switch, that will isolate the battery and you should try that first. If nothing changes, isolate the buss bar by finding the 12V circuit breaker with the tiny manual reset button and disconnect the wire on the output side (making sure you don't let it short against anything since it carries voltage from the power converter). Probably a good idea to disconnect shore power while working on the buss bar.

 

[brianharrison]

Would it work if I watched the meter as I pulled each fuze one at a time see if the drop in voltage stops (or slows dramatically) to isolate where the drain is coming from?

Right idea - but I would pull all the 12V fuses - repeat your voltage measurement test with all fuses out and then add the fuses back in one at a time - doing the same measurement test each time.

Brian

 

[brianharrison]

I will have to take the basement wall out again to see what the make and model of the converter is. Hopefully, I will get to that this evening.

The standard charger may be a Progressive Dynamics PD91XX series where the XX is the amperage outout (PD9165 for yours?) - if you are going into the basement tonight - follow this troubleshooting guide --> Troubleshooting PD9100 Series Power Converter.

Hope this helps.
Brian

 

[Rickhansen]

Would it work if I watched the meter as I pulled each fuze one at a time see if the drop in voltage stops (or slows dramatically) to isolate where the drain is coming from?

Yes, and I would pursue this, but my bet is that you have a bad converter.