2008 Cougar 26BHS, House lights dimming??

Firefighter1406 · 06-01-2022, 08:09 PM

2008 Cougar 26 BHS with interior lights that are dimming. As long as the converter is running they are nice and bright. As soon as it shuts off they dim. 5 seconds later the converter will kick back on again and the lights will brighten up. Battery gauge on the wall shows full. I am a dummy when it comes to electrical. Any help would be greatly appreciated. Currently camping and this is driving me nuts!!

**sourdough** · 06-01-2022, 08:23 PM

Batteries. When was the last time they were replaced, checked or watered?

Firefighter1406 · 06-01-2022, 08:59 PM

Quote:

Originally Posted by sourdough

Batteries. When was the last time they were replaced, checked or watered?

Watered over the winter while on trickle charge. Checked water again when installing them for this trip. Not sure how old, would venture to say it’s old, only owned the camper for two years however it looks older.

**chuckster57** · 06-02-2022, 04:31 AM

Take them out and load test them.

Firefighter1406 · 06-03-2022, 07:40 PM

Replaced the battery with a brand new one with larger capacity. Still doing it. Had the furnace running tonight and when the converter kicks off it slows down along with the lights dimming. Is my converter not putting out enough juice?

Firefighter1406 · 06-03-2022, 08:33 PM

If so how do I go about testing inverter output?

jsb5717 · 06-03-2022, 09:10 PM

Not your inverter, your converter. It sounds to me that it’s underperforming. Mine did the same thing. You can disconnect the batteries and, while plugged into shore power, test the battery leads with a meter to see what kind of output you’re getting.

Firefighter1406 · 06-04-2022, 07:06 PM

Did get a chance to do that today but will tomorrow. I mean correct me if I am wrong but shouldn’t I be able to run all the lights without them dimming? I mean the trailer was designed for this light load?? Also what kinda charging output am I looking for?

**chuckster57** · 06-04-2022, 07:08 PM

Quote:

Originally Posted by Firefighter1406

Did get a chance to do that today but will tomorrow. I mean correct me if I am wrong but shouldn’t I be able to run all the lights without them dimming? I mean the trailer was designed for this light load?? Also what kinda charging output am I looking for?

If your battery(s) are in good shape then yes the lights shouldn’t dim very much if at all. You want to see 13+VDC at the battery leads with it plugged into shore power.

**flybouy** · 06-04-2022, 07:32 PM

If your lights are the original incandescent bulbs then yes if turn every light in the trailer on then you'll drain down the battery quickly. In our trailer there are 12 light fixtures with 2 bulbs in each fixture and 3 with one lamp. Add 2 more in the outdoor kitchen, a porch light, a scare light, a light over the outside shower, hitch ligh up front, and two step lights. Also a fixture over the table and a wall sconce.

If they are 8 watt incandescent then that's around 250 watts @ 12 vdc. 250 watts ÷ 12 vdc = ~21 amps. Throw on the furnace and yes the lights will dim a bit. So if you could define "all the lights" and what your definition of dimming is it would help. Pay no attention to the "battery guage" leds in the panel. That's a voltage measurement so if the converter is charging it will indicate a "full" charge.

When you are plugged into shore power with all those lights on does the fan in the converter run?

**sourdough** · 06-05-2022, 07:44 AM

You replaced the battery (I would install a 2nd one). Check the converter for proper output (approx. 13.6vdc with battery disconnected reading from converter with shore power connected). Both OK? Personally I would replace every light in the RV with LEDs. Not a lot of expense and a whole lot of improvement. Will cut the drain on the battery dramatically and barring a failure of some kind, they won't be dimming. Get the 12-28vdc type and not the 12vdc only.

Firefighter1406 · 06-05-2022, 12:16 PM

Thank you all for your comments.

Yes the fan turns on in the converter.

I am getting 13.6 V with the battery disconnected.

When it starts dimming for me is having around 7 of the 2 bulb light fixtures on. Or 4-5 of the 2 bulb light fixtures with the furnace on.

I installed a Everstart MAXX Deep cycle battery. 845 Marine CCA and 114 AH at 1 Amp.

jsb5717 · 06-05-2022, 02:53 PM

What’s the amperage rating on your converter?

Firefighter1406 · 06-05-2022, 03:34 PM

Converter Output is 55Amp (inc charging and load).

Canonman · 06-05-2022, 04:46 PM

When you say the converter is running, is that because you're hearing the fan run?
When you are using shore power, the converter is always running. The cooling fan just runs when the converter is getting warm running at full output.
Your lights should work OK even without a battery as the converter is providing 12 vdc to the fuse panel. I'm guessing you may have a bad light fixture or bulb, or??. Have you tried turning the lights on one at a time to try and identify if one fixture is causing the problem?

Firefighter1406 · 06-06-2022, 05:26 AM

Yes I was meaning it was running when the fan is running but it makes sense what you were saying. It does run all the time. Doesn’t matter which light. As soon as I get to turn on the 4th 2 bulb light on the fan kicks on and within a few mins the dimming starts.

I can install another battery, I think I have enough space but have never seen a camper my size with two batteries so I never thought of it.

**JRTJH** · 06-06-2022, 06:13 AM

Quote:

Originally Posted by Firefighter1406

Yes I was meaning it was running when the fan is running but it makes sense what you were saying. It does run all the time. Doesn’t matter which light. As soon as I get to turn on the 4th 2 bulb light on the fan kicks on and within a few mins the dimming starts.

I can install another battery, I think I have enough space but have never seen a camper my size with two batteries so I never thought of it.

I would try a "troubleshooting trick" before you start spending money on a second battery (both should be replaced at the same time and be the same brand/size)....

Disconnect the battery from the trailer cables and make sure they aren't shorted or laying on anything metal. Then, plug into shore power and try your "on the 4th light, the fan starts and in a few mins, the dimming starts".... If, with no battery in the system, the dimming starts, it's likely a converter/charger issue... My thoughts are that with no battery connected, there will be no dimming. That would lead you to "a bad battery or bad/shorted cables in the charging line" (assuming the reverse polarity fuses are good)....

No need to buy a second battery, cause issues with damaging it if the current battery is bad and no need to buy a new converter if it's the battery that's causing the problem....

**flybouy** · 06-06-2022, 07:02 AM

Quote:

Originally Posted by Firefighter1406

Yes I was meaning it was running when the fan is running but it makes sense what you were saying. It does run all the time. Doesn’t matter which light. As soon as I get to turn on the 4th 2 bulb light on the fan kicks on and within a few mins the dimming starts.

I can install another battery, I think I have enough space but have never seen a camper my size with two batteries so I never thought of it.

I would suggest 2 things. First check the converter output voltage as has been suggested. Secondly, pull the bulbs out of those lights and see if they are marked with the wattage. They likely are a standard 921 wedge base bulbs but they come in many wattage ratings and other wedge base bulbs or even bi-pin lamps can fit in the sockets. So no telling what you may find. One disturbing find most people will see is the effect the incandescent bulbs have on the fixtures. The trapped heat will typically discolor or even melt the fixture. The LED lamps will run cooler and draw mutch less energy for an equivalent light output.

Firefighter1406 · 06-06-2022, 08:05 AM

Quote:

Originally Posted by JRTJH

I would try a "troubleshooting trick" before you start spending money on a second battery (both should be replaced at the same time and be the same brand/size)....

Disconnect the battery from the trailer cables and make sure they aren't shorted or laying on anything metal. Then, plug into shore power and try your "on the 4th light, the fan starts and in a few mins, the dimming starts".... If, with no battery in the system, the dimming starts, it's likely a converter/charger issue... My thoughts are that with no battery connected, there will be no dimming. That would lead you to "a bad battery or bad/shorted cables in the charging line" (assuming the reverse polarity fuses are good)....

No need to buy a second battery, cause issues with damaging it if the current battery is bad and no need to buy a new converter if it's the battery that's causing the problem....

Okay with the battery disconnected and the cables separated I tested it. The 4th light did kick the fan on the converter on. However I was able to run 6 double bulb fixtures and 1 singles bulb fixture without any dimming.

So I am confused as to why adding the brand new battery back in the mix causes the issues.

Should I just leave the battery disconnect switch off while camping and only use the battery when needing lights off shore power?

**sourdough** · 06-06-2022, 08:50 AM

You have tested the converter ouput and it's 13.6vdc as it should be. Your converter fan is kicking on when it reaches a particular load as it should. You replaced the battery but we don't know if it is actually "good" unless it is load tested (we would assume it is good). I suggested you have 2 batteries. I've always used 2 batteries for the last 30 years because one just won't cut it if you are ever off shore power in my experience or don't carry a generator. They do need to be the same brand and age so a bad one does not cannibalize the good one.

IMO once you start turning on 7 double bulb incandescent fixtures you are going to start seeing some dimming as the lamps and/or converter kick off and on, I've experienced that in the past. I am relatively certain that the replacement of any incandescent lamps with LEDs will alleviate this problem. Also, removing the incandescent lamps will cut electrical usage greatly along with heat at the fixtures. They're a win all the way around.

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