2014 Grand Design Momentum 355TH charging battery issues

[JohnTaylorTX]

My batteries dont seem to be charging, but not sure if its the converter or generator.
SO here is the history: I bought a used 2014 Grand Design Momentum 355TH last July and it worked great. Everything worked great and every time we used the generator it charged the battery (or kept them charged) after using them on many weekends for over 4 days straight each time. Then over the winter season I had the Camping World service some minor items and also some warranty items over the winter. I picked up the trailer a few months ago and it all seemed fine when we picked it up until this last weekend when we went to use it. Just note that right before we took it out for the weekend, I knew the battery was over a year old, so I bought a brand new Deep cycle battery plus verified with Batteries PLUS the battery was 100% charged, tested and good to go.
Now here is the kicker, which I did a mess up and hopefully it is just a fuse or something easy. Apparently the previous 'Multi' battery had the polarity of the positive and negative on opposite ends on which my new current battery was stated but ASSUMED it was the same. So, as you can guess when I tried to hook it up there was lots of sparks of course and pulled back the battery connection wires like wth??!
Anyway, I then realized the positive and negative had been switched. So I hooked it up normal and all seemed fine as I thought. Just an FYI, I have a total of 4 wires going to the battery:
2 wires, white one and a black one coming from Trailer.
2 wires coming from the internal generator.
So after this little incorrect hookup I went inside and noticed 3 fuses were blown, so I went to the O'Reilly Auto Parts store and bought brand new correct rated fuses and replaced the bad ones PLUS replaced old ones to have all fresh and 'correct' amp fuses and all looked good. In the main fuse box panel there was only 1 of the 40 amp fuse for the inverter or converter and it did show OK. Now I fired up the generator and tested everything and all is good to go and again at least I thought it was good to go since everything ran as normal (2 A/C units, 2 refrigerators, lights, etc, etc) for 30 minutes until I shut it down.
So the next day we drove and get to the track and set it all up. Unhooked from the truck, leveled it all out, slides out and then I started the generator. I then checked everything was on but then also noticed the battery level was now down to 2/3. I thought that was odd, as I drove it there with nothing on, plus I thought while connected to the truck it should be charging the battery right or no??
After about 4 hours of running on the generator and with dual A/C units, 2 refrigerators and lights all on, I then decided to check the battery level again and it was now down to 1/3 battery and I'm like WTH??!! I went and checked all of the fuses and checked all devices, plus made sure the battery wires and all grounds were nice and snug but could not find anything wrong. Well luckily there was a Autozone and I drove down there and bought a new deep cycle battery to have as a spare plus verified it was charged too. AS my main battery started to get low my Refrigerator was flashing LOW DC on the screen and sure enough my battery level now was showing empty. So I powered all A/C units off, switched refrig to propane and turned off all lights plus powered off the generator. Then I disconnected battery and replaced it with the brand new 2nd battery. Fired gen back up and turned everything back on and battery was 100% again. well about 10 pm I checked the battery level and it was back down to 1/3. Then about 3 am I hear multiple beeping from refrig and it showing LOW DC again, and confused now as it is on Propane and not even DC or AC and yup the battery level was back down to empty and Eventually about 30 minutes EVERYTHING powered off and in the dark, UGHH!! Luckily in the mean time I was charging up that other battery and did the old swap and was able to get generator back on and A/C units back on again. The next day was tiring during this about every 6 hours. SO, is it something in my generator not charging the battery or is it the Inverter or Converter? Also does the inverter or converter have their own fuse since there was only 1 of the 40 amp fuses in my main fuse panel? Please help as I just want it to work like it should. Many said my Converter fuse is blown or it is a bad Converter, but others said it might be my Inverter is bad as it could be pulling too much power from battery. Any way to test any of this or anyone have any ideas to check?

[howson]

My batteries dont seem to be charging, but not sure if its the converter or generator.
SO here is the history: I bought a used 2014 Grand Design Momentum 355TH last July and it worked great. Everything worked great and every time we used the generator it charged the battery (or kept them charged) after using them on many weekends for over 4 days straight each time. Then over the winter season I had the Camping World service some minor items and also some warranty items over the winter. I picked up the trailer a few months ago and it all seemed fine when we picked it up until this last weekend when we went to use it. Just note that right before we took it out for the weekend, I knew the battery was over a year old, so I bought a brand new Deep cycle battery plus verified with Batteries PLUS the battery was 100% charged, tested and good to go.
Now here is the kicker, which I did a mess up and hopefully it is just a fuse or something easy. Apparently the previous 'Multi' battery had the polarity of the positive and negative on opposite ends on which my new current battery was stated but ASSUMED it was the same. So, as you can guess when I tried to hook it up there was lots of sparks of course and pulled back the battery connection wires like wth??!
Anyway, I then realized the positive and negative had been switched. So I hooked it up normal and all seemed fine as I thought. Just an FYI, I have a total of 4 wires going to the battery:
2 wires, white one and a black one coming from Trailer.
2 wires coming from the internal generator.
So after this little incorrect hookup I went inside and noticed 3 fuses were blown, so I went to the O'Reilly Auto Parts store and bought brand new correct rated fuses and replaced the bad ones PLUS replaced old ones to have all fresh and 'correct' amp fuses and all looked good. In the main fuse box panel there was only 1 of the 40 amp fuse for the inverter or converter and it did show OK. Now I fired up the generator and tested everything and all is good to go and again at least I thought it was good to go since everything ran as normal (2 A/C units, 2 refrigerators, lights, etc, etc) for 30 minutes until I shut it down.
So the next day we drove and get to the track and set it all up. Unhooked from the truck, leveled it all out, slides out and then I started the generator. I then checked everything was on but then also noticed the battery level was now down to 2/3. I thought that was odd, as I drove it there with nothing on, plus I thought while connected to the truck it should be charging the battery right or no??
After about 4 hours of running on the generator and with dual A/C units, 2 refrigerators and lights all on, I then decided to check the battery level again and it was now down to 1/3 battery and I'm like WTH??!! I went and checked all of the fuses and checked all devices, plus made sure the battery wires and all grounds were nice and snug but could not find anything wrong. Well luckily there was a Autozone and I drove down there and bought a new deep cycle battery to have as a spare plus verified it was charged too. AS my main battery started to get low my Refrigerator was flashing LOW DC on the screen and sure enough my battery level now was showing empty. So I powered all A/C units off, switched refrig to propane and turned off all lights plus powered off the generator. Then I disconnected battery and replaced it with the brand new 2nd battery. Fired gen back up and turned everything back on and battery was 100% again. well about 10 pm I checked the battery level and it was back down to 1/3. Then about 3 am I hear multiple beeping from refrig and it showing LOW DC again, and confused now as it is on Propane and not even DC or AC and yup the battery level was back down to empty and Eventually about 30 minutes EVERYTHING powered off and in the dark, UGHH!! Luckily in the mean time I was charging up that other battery and did the old swap and was able to get generator back on and A/C units back on again. The next day was tiring during this about every 6 hours. SO, is it something in my generator not charging the battery or is it the Inverter or Converter? Also does the inverter or converter have their own fuse since there was only 1 of the 40 amp fuses in my main fuse panel? Please help as I just want it to work like it should. Many said my Converter fuse is blown or it is a bad Converter, but others said it might be my Inverter is bad as it could be pulling too much power from battery. Any way to test any of this or anyone have any ideas to check?

The converter in your trailer has fuses that are there to blow if the batteries are hooked up backwards.

When you swapped out the blown fuses, did it include the two in this picture?

[JohnTaylorTX]

I only swapped out the fuses in the main fuse box, that has all of the fuses for the entire trailer. I will have to find and pull out the converter, and see if the fuses are just blown on the Converter itself. I am hoping it is as simple as that. I will look tomorrow, thank you.

[JCR GD]

With a polarity swap the fuses on the converter are most certainly blown. Hopefully that will be the end of the problems!

[JohnTaylorTX]

Thank you for your replies. I will take a look at the converter fuses today. Just out of curiosity if the converter is behind the main fuse control panel box, then how do you get the cover off to look at the converter?

[ncitro]

It must be the converter fuses. The generator does not charge the batteries directly, it provides 115V to the converter which then runs all your 12v appliances (when the rig is rig is either plugged in or the generator is running) and charges the battery. If the converter fuses are blown you’re not getting power from your generator to the battery to charge it or run your 12v appliances.

Fyi your refrigerator requires 12v to run the control board regardless of whether it is on propane or electric.

[bertschb]

I'm not sure about your Momentum 355TH but the converters on all three of my Grand Design 5th wheels were behind the wall in the basement 2'-3' from the rear of the electrical panel. The easiest way to access it is to remove the screws that hold the basement wall in place. Be prepared though! You will see a rats nest of wiring that will freak you out if you have OCD.

[ncitro]

I'm not sure about your Momentum 355TH but the converters on all three of my Grand Design 5th wheels were behind the wall in the basement 2'-3' from the rear of the electrical panel. The easiest way to access it is to remove the screws that hold the basement wall in place. Be prepared though! You will see a rats nest of wiring that will freak you out if you have OCD.

Yes I would think either there or sometimes I’ve seen them at the bottom of the fuse panel after you take the cover of the panel off.

[JohnTaylorTX]

We looked all over the Toy hauler and we could not locate the Converter. In many other posts they say it is located underneath the fuse control panel box. We do not have an extra area underneath the fuse control box where in some cases the Converter would sit as pictured. We removed the cover of the fuse control box and looked behind it plus even removed the control box above it to see if maybe they mounted the converter behind either the fuse box or the main switch box, but the converter is not there. Would anyone know where the converter is located at for our 2014 Grand Design Momentum 355TH ?

[Cate&Rob]

Would anyone know where the converter is located at for our 2014 Grand Design Momentum 355TH[/ATTACH]

The aft wall of the pass through storage area is removable (a few screws down each side of the panel) to access many plumbing connections, the water pump, the furnace, the water heater . . . and the converter. This is a good area of your RV to become familiar with .

Rob

[JohnTaylorTX]

So I finally found the converter in my 355TH and Yes both of the 40 amp fuses were blown on the Converter. In the front lower storage 'basement' area on the back wall (middle area) there was a wall at an angle that had 6 screws on it (3 down each side). I took this wall off and looked in that area first, which we did before and could not find the Converter but tons of hoses pipes and wiring. Obviously before touching ANY electrical I removed the Battery disconnect to OFF, plus I removed the wiring to the battery too.
Well, this time I decided to look further BEHIND the main basement wall and move wires and there it was under some wiring and mounted to the floor. Note that with the wall there and a pipe plus wiring I could not crawl in there, so I had to use my arm to reach way in there and down on the back of the converter to pull out each fuse. 1st fuse was indeed blown, so I put it back as a reference and pulled the 2nd fuse and well yup that was blown too. Went to the Autozone and bought new 40 amp fuses and replaced them in the converter. Hopefully this fixes my battery charging issue and the converter isn't fried but we will be testing it this next weekend. I attached a picture of the two fuses that were blown as one was literally burnt bad too.

THANK YOU for all of your suggestions and help on trying to resolve this battery charging issue.

[TucsonJim]

Here's a helpful tip for all owners. Before disconnecting any wires on your batteries, wrap the ends of the positive wires with red vinyl tape. And the wrap the ends of the negative wires with black vinyl tape. Most of us are familiar with red = positive and black = negative.

Jim