Converter Box, Lights are brighter and dimmer

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DearMissMermaid

DearMissMermaid

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on the move USA
Just wondering...

I have converter box, I am plugged into campground.

Is it normal for 12 volt current to fluctuate from the converter box?

Sometimes my 12 volt lights are brighter and sometimes dimmer.

Some are LED and some are regular 12 volt.

 
When plugged into shore-power and not running heavy loads (like a microwave oven) it is not normal for 12 volt lights to fluctuate in brightness. Minor A/C power fluctuations at a power pedestal are not unusual, but major fluctuations can cause serious problems - both high and low voltage fluctuations.

To troubleshoot, you might want to try running the same lights/devices while on generator power. If the lights still fluctuate in brightness, it could indicate a problem in the coach - perhaps with the converter. If the lights stop fluctuating in brightness while on generator power, there may be a problem with the power coming into the coach.

Are you using a surge protector of any kind? The more expensive ones check for a number of electrical problems, including high and low voltage conditions, and will automatically cut power to the coach if certain parameters are met. They're a good investment IMO.

Kev
 
Asking ya'll out of ignorance-could a weak/bad battery cause fluctuations? Seems a bad battery would not be providing the "cushion" during higher demands, and possibly using up power from the converter trying to keep a bad battery charged.
 
DearMissMermaid said:
Just wondering...
I have converter box, I am plugged into campground.
Is it normal for 12 volt current to fluctuate from the converter box?
Sometimes my 12 volt lights are brighter and sometimes dimmer.
Some are LED and some are regular 12 volt.
Click to expand...
DearMissMermaid
What is a "converter box" and what does it have to do with the 12V lights?
 
A Converter takes incoming 120VAC power and converts it to 12VDC, which is used to keep the battery charged and supply 12VDC current to the coach.  In some setups, the converter only feeds the battery, which then feeds the coach.  Newer setups have the converter feeding both, so you can run without a battery when connected to shore power.

DO NOT TOW WITHOUT A BATTERY  This is what supplies power to the brakes in case of a break away.

It would be possible for a bad battery to draw lots of power - dim lights - when charging, and brighter lights when supplying 12VDC without charging, once the battery appears charged.  The bad battery soon would bleed down, and need charged again.
 
When our coach did that, it was the converter going bad.  The converter was also over charging the house batteries, about 17 volts.
 
grashley said:
DO NOT TOW WITHOUT A BATTERY  This is what supplies power to the brakes in case of a break away.
Click to expand...

grashley
I agree.
BTW the OP has a class C motorhome.
 
I realize that.  Miss Mermaid is smarter than that, too.  That comment was for future readers who may not know!
 
What bothers me is Miss Mermaid asked that question, and hasn't been back since. That's not like her. I pray she's doing ok.
 
I would like to jump in here. I am having a 12v coach problem. I have installed 2 new matching deep cell marine batteries, then I replaced the converter. Now the 12v coach power works as long as I am running off shore power or generator. If I shut down 110 v. current no 12 v. lights work. This has been this way for over a week. As a test I shut down all 110 v. power and ran a jumper wire from pos. battery to 12v fuse block. everything worked!

what next solenoid? aux disconnect switch? help please.
fyi I am in central Kentucky

edit: corrected typo. -ls
 
Blown fuse. bad fuse block, bad battery cable.
 
As you have 12vdc when the generator is running or hooked to shore power, the converter is working to provide 12vdc to house systems.  While either is supplying AC, take a volt meter (digital works best) and check the voltage across the batteries ... you should see something on the order of 13.2 vdc or a little more.  I'd be willing to bet (a little  ;D  ) that you will be seeing 12v or lower.  If so, that is telling you the batteries are not connected to the house system.

#1 is usually the battery disconnect switch is in the store/disconnect position.

#2 as you just recently replaced the batteries I would look there for a wire that was missed and not reconnected.
 
There are many of us here who could raise our hand to the .... "Don't ask how I know that " question.  ::)  ;D

Let us know what you find out.

Howard
 
I just tested the batteries as you suggested and you are right. With a digital multi meter it reads 12.42 v.
I guess the next thing i will do is figure how to get at the solenoid. I can see and hear it click but it is not going to be easy to get at it. that will be tomorrows project.
 
By the way...what are you working on...make, model, year?  You can go to top of page and click on profile, then Forum Profile and add it to your signature.  That will help us help you.  :)

Howard
 
.... then I replaced the converter. Now the 12v coach power works as long as I am running off shore power or generator.
Click to expand...

Makes and models of both old and new are important here as the wiring methods needed may be different.
 
Hey Miss Mermaid, did you ever get this straightened out? If so, what was wrong?
 
kdbgoat said:
What bothers me is Miss Mermaid asked that question, and hasn't been back since. That's not like her. I pray she's doing ok.
Click to expand...

Aw thanks for thinking of me. I was overwhelmed, still am!

Trying to stay on top of maintenance or finding someone to reasonably work on rig that actually knows their stuff is like a needle in a haystack.

Nothing fixed on converter box. It might be I just need to replace the bathroom light, as that is where I am seeing the wild fluctuations in lighting, or else my aura is just going on off intermittently.

I discovered my converter fan seems to work randomly, it might need replacing. I know it shoudl cycle on for heat and so on. It's $60 for just the fan. This is the 2nd comverter in this rig, I didn't replace it, came with a retrofit  when I bought it.

My rig is only  23 years old.

How could anything dare to go wrong?
 
The common cause for that sort of thing is a bad battery. The converter/charger tries valiantly to charge it and sends major amps to the battery, momentarily dimming the lights. Then the charger realizes the load is too great and cuts back on the charging amps and the lights get bright again.  Then the cycle repeats the next time the charger samples the battery states and sees the charge level is low.

A poor quality connection on the battery terminals or at the connection to the 12v fuse panel can have the same effect.

A smarter converter/charger will minimize the side effects, but that eliminates the symptom more than fixing the problem.
 
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