Help With Lights Going Bright to Dim

[Forbes]

Have two Duracell glass 12 volt batterys, 950 watt system in 36RE. Problem is lights keep cycleing bright to dim to bright etc. Have check all connections that can be found, insured fan on chargeing unit working and have found nothing that stops this, any one had this or know how to inprove or stop...

[TURBS]

Originally Posted by Forbes

Have two Duracell glass 12 volt batterys, 950 watt system in 36RE. Problem is lights keep cycleing bright to dim to bright etc. Have check all connections that can be found, insured fan on chargeing unit working and have found nothing that stops this, any one had this or know how to inprove or stop...

Need to check converter.
What model and brand is it?
Need to load test batteries as well.

[Forbes]

The power converter is a WFCO WF-9845 a 45 amp unit. I have done a battery load test and they are fine. I will doing a output test on the WF-9845 tomorrow in day light. I think the unit might not be putting out high enough amperage when the lights are on in RV unit. It appears to be chargeing the batteries but not able to keep up with lights as will as battery charge. Does this make any sense at all or am I barking up wrong tree? I placed a good battery charger on batteries and turned off the converter and the diming stopped.

[CapitolPCO]

Check the converter main wires. FR trims them so they fit into the converter and that cuts the amps.

[VinceU]

Originally Posted by Forbes

Have two Duracell glass 12 volt batterys, 950 watt system in 36RE. Problem is lights keep cycleing bright to dim to bright etc. Have check all connections that can be found, insured fan on chargeing unit working and have found nothing that stops this, any one had this or know how to inprove or stop...

You really need to connect a DC voltmeter to the battery posts and separatley to the converter output. It almost sounds as though the batteries are not connected to the converter output and DC bus. One of the prime reasons to maintain a battery in the coach is to smooth out the DC voltage mfg. by the converter, its not pure DC and battery cushions the output. The lights as you describe are swinging by at least 3-4 volts and this can damage electronic circuits in fans, refrigerator etc. The swing output of the conveter esp if connected to batteries is severe and can be caused by a defective voltage regulator circuit. Can usually be repaired but most on this forum reccommend get rid of bad WFCO converters for Progressive Dynamics, mine is neither. I would recommend stay with you battery charger and get the converter off the bus until repaired or replaced.

[Apache Dave]

I have a 2006--33 Ft 5th wheeler--Cedar Creek Silverbear 33LRLBS--50 amp system main breaker --my issue is the converter. I believe mine is burnt out. I have battery lights (new batteries installed about 4 months ago). Once connected to either 30 amp or 50 amp outlet my lights will not brighten up. I would like to know if only converter can be changed out or do I have to change out complete breaker system with converter unit combo? Please advise.

[VinceU]

Originally Posted by Apache Dave

I have a 2006--33 Ft 5th wheeler--Cedar Creek Silverbear 33LRLBS--50 amp system main breaker --my issue is the converter. I believe mine is burnt out. I have battery lights (new batteries installed about 4 months ago). Once connected to either 30 amp or 50 amp outlet my lights will not brighten up. I would like to know if only converter can be changed out or do I have to change out complete breaker system with converter unit combo? Please advise.

Check the dc voltage at the battery out posts with a meter. W/o shore power should be ~12.4. With s/p should be 13.2+. Many converters but not all, are in the lower half of the power panel
Below circuit breakers. I don't think all style lights brighten with one volt increase. Anyway the v/m readings will tell.

[fly fish]

We just purchased an 07 Cedar Creek 34 SATS and did a three day stay at a new RV park near Shelton, Wa. We also noticed voltage variation and light dimming as well as furnace blower variation. During our stay we switched from 30A to 50A hookup and found that a lot of the variation went away untill the last day when the park was filling up for New Years week end. I appreciate all the above thoughts and will check out my charger system and battery. I was just wondering if anyone had used a surge protector/voltage regulator with good results?

[Herk7769]

I believe most (if not all) of these issues can be solved by checking/cleaning your ground connections.

A corroded ground connection will cause havoc with your 12VDC system.

[fly fish]

Thanks for your quick reply. Seems to me that I had to clean up the grounds on my last fifth wheel. I will check them out.

[Herk7769]

Don't forget the terminals on your inline current limiters. They are exposed to the elements and can look good from the outside but be corroded where they are making contact.

[wildcatmlm]

I'm having the same dim-bright-dim problem with my Georgetown but not when running on the coach batteries. this happens when plugged in to shore power. It happens at both 30 amp and 50 amp power. The funny thing was that the lights became bright when I turned on my hair dryer which would pull quite a bit of power. Would this be caused by my converter going bad? Wildcatmlm

[RenoRock]

It's possible that your converter/charger cannot keep up with the sometimes demand on the DC system. The lights may seem fine when your converter is on maintenance or trickle charge more, and when there is a heavier draw the converter moves into quick charge mode boosting the voltage a bit and presenting you with brighter lights for a short term.
My first move here, although it may not eliminate the problem, would be to move up to a more powerful converter. You may still see the brightening, but it may occur at a less frequent rate.

[puff]

Forbes

Pull the switch for your lights out and have a look. If it is like mine the panel is only held in with 4 screws and look at the back of the switch that controls the lights. In my 2011 36RE the switch overheated and was melting at the connection.

I have found that when I was using my 12v lights and the inverting was kicking in the lights did change in intensity a small amount however, after changing to L.E.D. lights the issue has gone away.

[wildcatmlm]

Thanks Reno Rock-
I'll pass your suggestion onto my "RV guy" at the dealership that does work on my RV. I told them last year about the problem but was told they couldn't find any problems and that it was probably a problem with the campsite hookup. It's done it no matter where I am and at all levels of power. It just seems funny that it was dimmest last weekend when the only draw was one tv and the ceiling lights in the main front area and they brightened when I used the hair dryer. Lights went dim again when I turned it off.

[wildcatmlm]

Which light switch do I pull out? The main cabin light switch? headlights? All of them? After having a motorhome for 4 yrs I'm getting pretty good at pulling things out, plugging pipes if I have an idea where to look.

[puff]

Light switch for the main cabin in the 5th wheel, should be a panel by the closet. I found it easier to pull the whole panel out. Check the switch and the wire to the switch.

[wildcatmlm]

Thanks Puff-
I have a class A Georgetown. I know where the switch for the main cabin is and it's easy to get to (right by the entry stairwell). I'll check that tonight.

[TURBS]

Do the lights get brite and dim only when using a 110v item or theve been doing it without 110 usage as well?

[DougP47]

When we brought ours home from buying it new I did a check off all wiring I could get to. I found loose connection on terminal block for the battery and wiring goes to the power panel inside the tt. I tightened them up before I had any problems. I had to replace a crimp connector also, The crimp only had about ¼ ‘wire inside of it. sanded all paint off the frame for ground connection as well. Best of luck with yours.