2021 Tab 320- battery not powering trailer

I brought my 2021 Tab 320s home from the dealer yesterday and have had a pile of problems since - this one involves the electrical. Nothing in the trailer can be powered by the battery. First I found that the in line fuse was blown so that was replaced. At that point the battery was reading 12.6v. After charging all day on shore power with the battery disconnect set to green (ie, battery was connected) the moment I unplugged from shore, everything shut off. I checked the fuses/breakers in the inverter box and nothing is blown. Everything worked when hooked up to shore power. Is there another fuse to check? Is it possible that the battery just isn't hooked up to the trailer? Thanks for the help.

Comments

  • Sharon_is_SAMSharon_is_SAM Moderator Posts: 5,197
    I assume the battery reading was after you disconnected shorepower as while on 120 v it should read 13.6.

    How did you measure the battery voltage?  Meter or the TaB KIB monitor?
    Sharon / 2017 [email protected] CSS / 2015 Toyota Sienna Minivan / Westlake, Ohio
  • trimtabtrimtab Member Posts: 80
    Inquiring mind wants to know too (we pick our up tomorrow)
    2020 320-S, solar, etc.
  • CaptenajCaptenaj Member Posts: 10
    Thanks for the response. The guy from the dealership measured it with a meter. He was the one who replaced the fuse.
  • Sharon_is_SAMSharon_is_SAM Moderator Posts: 5,197
    I don’t have the KIB monitor.  Does it have a voltage display?  If not, you can get a plug in battery monitor.  

    You may have a bad battery.  It’s not unheard of.   I would take it to a battery shop and have it tested (independent of the dealer). 
     
    Sharon / 2017 [email protected] CSS / 2015 Toyota Sienna Minivan / Westlake, Ohio
  • ScottGScottG Moderator Posts: 3,506
    edited May 21
    Captenaj said:
    ...
    Is it possible that the battery just isn't hooked up to the trailer? Thanks for the help.
    From what you describe, yes--though that can occur in a number of ways.
    If the battery initially tested at 12.6V, it should be good enough to provide some juice when you disconnect from shore power.
    Since everything works on shore power, then the converter itself and the 12V DC distribution system are also probably fine.
    That leaves a broken circuit between the battery and the converter as the most likely culprit. Short of a broken wire (not likely) this can occur at several locations:
    1. battery not hooked up or properly grounded
    2. 30A fuse at battery blown
    3. faulty contact or connection at disconnect switch
    4. disconnected lead at primary j-box
    5. battery positive lead disconnected at converter
    6. 30A battery lead fuse in converter blown
    7. 40A battery reverse polarity fuse in converter blown
    8. faulty contact in converter battery circuit
    If you haven't done so already, check #2 again. That fuse blew once for a reason, and if that reason is not corrected it will blow again as soon as you restore power.

    If the fuse checks out, move next to #5. The trailer's DC wiring is connected to the converter with bullet-type quick connects under the driver's seat at the back of the converter. Make sure these are all tight, particularly any involving a heavier red wire, as that will be the lead from the battery.

    Ultimately, it's a matter of tracing the path between the battery and the converter and confirming all connections. A multi-meter that tests both voltage and continuity can facilitate this. Electrical problems can range from very simple (like a disconnected wire) to frustratingly complex (like a hidden short within a component). Good luck and let us know what you find! 

  • CaptenajCaptenaj Member Posts: 10
    Thank you for the help! The culprit was the 7.5A inline fuse on the battery. The dealer came out and replaced the 10A, said I was good to go and took off. I thought the problem was solved but the electric was working because I was plugged in (yes, a brand new owner here!). I didn't know, nor did the dealer apparently, that there was a second fuse on the battery. I have a 5A in there now until I can get a hold of a 7.5A. Thank you again!


  • Sharon_is_SAMSharon_is_SAM Moderator Posts: 5,197
    I don’t remember having a second fuse.  Is that on the solar port  wire?
    Sharon / 2017 [email protected] CSS / 2015 Toyota Sienna Minivan / Westlake, Ohio
  • jkjennjkjenn Member Posts: 5,750
    I don’t remember having a second fuse.  Is that on the solar port  wire?
    Had the same question.

    2015 320 S | [email protected] Nights: 211 | 2018 Jeep Grand Cherokee Trailhawk

  • VernaVerna Administrator Posts: 5,672
    The battery should have a 30amp in-line fuse. Unless I’m seeing it incorrectly, there is a 5 amp and a 10 amp. 
    Verna, Columbus, IN, 2019 [email protected] 400 Boondock Lite white/red, towed by a white 2019 Ford F-150 4x4 Supercab, 3.5L V6 Ecoboost; [email protected] Administrator
  • CaptenajCaptenaj Member Posts: 10
    You are seeing it correctly. It came from the dealer with a 10A and a 7.5A, both of which were blown. The dealer came out, saw the 10A was blown, and replaced it with another 10A. After he left and things still weren't working, I found that the 7.5A was blown so I replaced it with what I had, a 5A. That lasted until I unplugged shore power and presumably the refrigerator kicked on.

    The Tab has solar so it could be the second fuse has something to do with that. All I know is when that fuse has blown, the trailer has no power even though the battery is charged.

    The cover on each fuse says "Max 30A." Is that for real and can I put 30A fuses in each? Or does that mean the cover is rated to 30A but my system may not be. As you can tell, I'm rather new to electrical systems. Thanks for the help.
  • Sharon_is_SAMSharon_is_SAM Moderator Posts: 5,197
    Maybe someone with factory solar can confirm what size fuse is needed?  
    Sharon / 2017 [email protected] CSS / 2015 Toyota Sienna Minivan / Westlake, Ohio
  • VernaVerna Administrator Posts: 5,672
    edited May 22
    Okay, I have the 400, so I can’t get to my batteries. 

    If you can trace the wiring, the wire that goes to the battery switch should have a 30 amp fuse in it. I think, my 200 watt Zamp suitcase has a 20 amp fuse in it. So, what ever wiring goes to the solar try putting a 20 amp fuse in it and see if that works. 
    Verna, Columbus, IN, 2019 [email protected] 400 Boondock Lite white/red, towed by a white 2019 Ford F-150 4x4 Supercab, 3.5L V6 Ecoboost; [email protected] Administrator
  • jkjennjkjenn Member Posts: 5,750
    Captenaj said:
    You are seeing it correctly. It came from the dealer with a 10A and a 7.5A, both of which were blown. The dealer came out, saw the 10A was blown, and replaced it with another 10A. After he left and things still weren't working, I found that the 7.5A was blown so I replaced it with what I had, a 5A. That lasted until I unplugged shore power and presumably the refrigerator kicked on.

    The Tab has solar so it could be the second fuse has something to do with that. All I know is when that fuse has blown, the trailer has no power even though the battery is charged.

    The cover on each fuse says "Max 30A." Is that for real and can I put 30A fuses in each? Or does that mean the cover is rated to 30A but my system may not be. As you can tell, I'm rather new to electrical systems. Thanks for the help.
    Try replacing that 10a with a 20a or 30a fuse. A 10a fuse seems ways too small.

    2015 320 S | [email protected] Nights: 211 | 2018 Jeep Grand Cherokee Trailhawk

  • ScottGScottG Moderator Posts: 3,506
    @Captenaj, to the best of my knowledge, the fuse for the solar should not be relevant here, as it only connects the solar controller to the battery. If it blows you won't get any solar charging, but a charged battery should still be able to power the trailer.
    However, the other fuse--the one that connects the battery to the converter--is important. If that blows you have effectively disconnected the battery from the trailer. Every other [email protected] 320 I'm aware of has a 30A fuse in that location. Why yours has a 10A fuse is anybody's guess, but I think you are on to something with your comment about it lasting until the fridge presumably started up. The whole idea of a fuse is to prevent too much current flow--in this case the trailer is designed to deliver 30A but you are only allowing 10A before the fuse blows. Here's what I suggest at this point:
    1. If you haven't done so already, determine for certain which fuse is which.
    2. Pull BOTH fuses and check the voltage directly at the battery terminals. It should be >12.5V. (This step is important because if you measure battery voltage with something hooked up you may not get an accurate reading.) If the battery is <12V it needs to be charged and may even be faulty.
    3. If the battery checks out, replace the main fuse (the one connecting the battery to the converter) with a 30A fuse. Leave the solar fuse out for now. Check all your systems to see if you have 12V power to the trailer.
    4. If everything checks out, replace the solar fuse with one that is the proper size for your solar controller. Ensure that everything is still working.
    If you are still blowing fuses at this point (or otherwise don't have power) then we will need to dig a little deeper as there is probably an open or short circuit somewhere that is wreaking havoc. Report back what you find and we'll go from there!
  • Sharon_is_SAMSharon_is_SAM Moderator Posts: 5,197
    @Captenaj, since you are a newbie and electrically naive (we all were at some point ☺️), I will throw this out to hopefully prevent future fuse issues.  Remember to always turn off your Alde at the control panel before disconnecting shorepower.  By doing so, you prevent an electrical surge to the Alde when you next plug in to shorepower.  That surge can and will blow the Alde fuse and you will be without heat or hot water.  The effected fuse is in the Alde - not at the 12 v fuse panel.  As a rule, we turn off everything before unplugging.  Hope this spares you future fuse issues and BTW, make sure you purchase extra fuses just in case :)
    Sharon / 2017 [email protected] CSS / 2015 Toyota Sienna Minivan / Westlake, Ohio
  • trimtabtrimtab Member Posts: 80
    " Remember to always turn off your Alde at the control panel before disconnecting shorepower." Thank You.  Another newbie here.
    2020 320-S, solar, etc.
  • jkjennjkjenn Member Posts: 5,750
    I haven't done any scientific study, but I have never had issues blowing fuses and have noticed that others who use an Elcrtical Management Systems (EMS), like the Progressive Industries units don't seem to blow fuses, either. These systems protect your trailer from power surges, reverse polarity, and RV, "hot skin". 

    Mike Sokol has provided tremendous education to the RV community about safety related to rv and electricity over the years: 
    https://rvelectricity.com/articles/

    2015 320 S | [email protected] Nights: 211 | 2018 Jeep Grand Cherokee Trailhawk

  • mntrailsmntrails Member Posts: 3
    This topic gives me one more question on the list for the dealer orientation when I pickup our 320S next week - 'please show me where every fuse is located and what are the values of each'.  Plus will be sure to run things on both battery and shore power for a few minutes.  Thanks for the ideas!
  • VernaVerna Administrator Posts: 5,672
    @mntrails, if you search for “Fuses for Newbies”, Tabaz put together a wonderful collection of which fuse is where and what it protects for the 320.
    Verna, Columbus, IN, 2019 [email protected] 400 Boondock Lite white/red, towed by a white 2019 Ford F-150 4x4 Supercab, 3.5L V6 Ecoboost; [email protected] Administrator
  • dragonsdoflydragonsdofly Member Posts: 1,244
    @mntrails, another suggestion is to video your orientation with the dealer. Sometimes, there is so much information to absorb that you naturally forget some of the topics or details. If you record the orientation, even just on your phone, you will have something to refer back to.
    2017 [email protected] sofitel([email protected])TV 2015 Silverado 2500hd(Behemoth). Wyandotte, Michigan.
    Draco dormiens numquam titilandus.
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