2014 GRAND DESIGN Momentum 355TH battery charging issues

[JohnTaylorTX]

My batteries dont seem to be charging, but not sure if its the converter or generator.
Here is the history: I bought a used 2014 Grand Design Momentum 355TH last July 2019 and it worked great all year. 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, 1 white one and 1 black one coming from Trailer. (hopefully hooked up right now?)
2 wires, 2 THICK BLACK wires coming from the internal generator. (hopefully hooked up right now?)
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 in correct spots 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 a swap and was able to get generator back on and A/C units back on again. The next day was tiring doing 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. Is there any way to test any of this or anyone have any ideas to check?
​​​​​

[gbkims]

...Anyway, I then realized the positive and negative had been switched.
...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. Is there any way to test any of this or anyone have any ideas to check?​​​​​

The reverse polarity fuses that are on the converter blow immediately when the battery is connected reversed.

WFCO 9800 Series: https://wfcoelectronics.com/wp-conte...Manual-web.pdf

"Reverse Polarity Fuses
If there is no DC output coming from the WF-9800 Series Converter-Charger output lugs, first check the reverse polarity fuses on the rear panel. Then, visually inspect the fuses for any breaks in the fuse element. If no breaks are found, use a continuity tester to check for continuity. If the reverse polarity fuses are blown, it means the RV battery was accidentally connected in reverse, either at the battery or at the converter. Investigate the connections and reconnect the cables properly. Replace the fuse with the same type and amperage rating as the original.

IMPORTANT: These fuses protect the converter from damage if the RV battery is accidentally connected in reverse. A reversed battery connection, even if for only a second,
will cause these fuses to blow.

If the above checks have been made but the converter output still reads 0.0 VDC, the converter is not functioning properly."

[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 ?

[gbkims]

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 ?

Converter plugs into an outlet that's on the back of the panel and probably is mounted on the basement floor.
It's 120VAC circuit breaker on the panel would be the one labeled CONV.
And its DC reverse polarity fuses are on the converter.
Pict of another Momentum's basement with converter on left.

[Redapple63]

Here is the converter in my Reflection. As was previously stated it plugs in close to the 12v and 110v fuse box and circuit breakers.

[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.