RESOLVED: T@B 320S not getting power from the tow vehicle

GibWGibW Member Posts: 95
2017 T@B 320 S.  Not receiving a charge when hooked up to the TV’s 7-pin. Tested the TV with a multimeter and all is good there. 7-pin plugs are clean. Battery cutoff is turned on and battery fuse is good. Tested fuse holder as directed by dealer with multimeter and showing a charge on the battery side but nothing on the other side. Checked the junction box under the trailer and all looks good.  Thoughts for trouble shooting?

Resolution... I took the trailer to our dealer, Elk River RV (MN). They found an intermittent short in a fuse holder on the 12V power line coming from the TV's battery. They replaced the fuse holder and now it works. Also, learned that the TV's lights must be on in order for the TV to deliver 13.7 volts for charging. A shout out to the crew at Elk River - they provided EXCELLENT service, working us in to their already booked schedule. We are so glad we bought our T@B from them. Thanks also to all on the forum and T@B Facebook page who weighed in with diagnostics/solutions.
2017 T@B Max-S, silver & silver, towed by a Titanium Silver 2018 Kia Sorento AWD V-6, Twin Cities MN

Comments

  • Sharon_is_SAMSharon_is_SAM Administrator Posts: 9,460
    Looks like the TaB 7 pin cable is at fault.  Sometimes the pins can bend just slightly enough to prevent contact.  Check out the 12 V pin at 11:00.
    Sharon / 2017 T@B CSS / 2015 Toyota Sienna Minivan / Westlake, Ohio
  • GibWGibW Member Posts: 95
    Sharon_is_SAM...Thx.  Will do
    2017 T@B Max-S, silver & silver, towed by a Titanium Silver 2018 Kia Sorento AWD V-6, Twin Cities MN
  • ScottGScottG Administrator Posts: 5,395
    Bumping this just to call attention to the edited original post which describes the resolution. Thanks for the followup, GibW!
    2015 T@B S
  • lkc001lkc001 Member Posts: 731
    Post this as another good dealer to do business with!
    2016 Nissan Frontier SV V6 4x4
    Finally!  New Owner of a 2017 Tab 320S! 
    Woohoo!
  • BaylissBayliss Member Posts: 1,299
    @GibW, it seems odd that your tow vehicle lights must be "on" for it to deliver 13.7v to charge the trailer battery.  Did your dealer provide any explanation as to why that is?  I don't turn on my lights on my 2007 Toyota Tundra while towing and it seems to charge my camper battery fine.  Glad you resolved the issue.  Thanks!  (Greg) 
    2019 T@B 320 S Boondock Lite2007 Toyota Tundra 4x4
    (Alde: 3020; Refrig: Isotherm Cruise 65 Eleg; Battery: BB 100Ah LiFePo4; Solar: Renogy 100Ah Suitcase; Victron BMV-712; Pwr Cntr: PD-4135KW2B; EMS: PI-HW30C)
    Greg & Marlene (Tucson, AZ)


  • MarcelineMarceline Member Posts: 1,497
    Bayliss said:
    @GibW, it seems odd that your tow vehicle lights must be "on" for it to deliver 13.7v to charge the trailer battery.  Did your dealer provide any explanation as to why that is?  I don't turn on my lights on my 2007 Toyota Tundra while towing and it seems to charge my camper battery fine.  Glad you resolved the issue.  Thanks!  (Greg) 
    My understanding is that the tow vehicle’s alternator output may be controlled by an onboard computer, and that computer will order a higher output when the vehicle’s headlights are turned on. But this may be specific to certain vehicles. 
    San Francisco Bay Area
    2013 CS-S us@gi
    Battered but trusty 3.5l V6 Hyundai Santa Fe
    2015 Toyota Tacoma PreRunner Double Cab
  • GibWGibW Member Posts: 95
    Exactly. Many of today's autos have "smart" alternators that only produce a charge when sensors tell it that it's needed. This is intended to save fuel and enhance efficiency. This is what happens with our Kia. When the engine is running and lights are off, the charge line only shows 12.5 or 12.6 volts or the amount of charge in the vehicle's battery. But when the lights are on, the charge line shows 13.7 volts. My understanding is that many trucks do not have this feature as fuel efficiency is less of an issue but I would also guess that this may be changing especially with the new breed of mid-size pickups.
    2017 T@B Max-S, silver & silver, towed by a Titanium Silver 2018 Kia Sorento AWD V-6, Twin Cities MN
  • davel4wadavel4wa Member Posts: 91
    A short in a fuse holder is it's normal state, by the way. What you had was an intermittent open. Wouldn't it be nice if dealer personnel would inspire us with their knowledge and correct use of terminology. 
  • davel4wadavel4wa Member Posts: 91
    Alternators in automobiles have built in voltage regulators and have for decades. It is the job of the regulator to keep the output voltage of the alternator at the proper level by varying the exciter current in the alternator. At idle speeds it's not uncommon for the voltage to be close to the static battery voltage. As the engine speed increases or as the electrical load increases the alternator output voltage will increase to a level sufficient to keep the battery charged and supply current to the load. There is nothing special about this. What some vehicles have, particularly those equipped for towing, is a relay that controls the power supplies to the towing harness.
  • ArtArt Member Posts: 5
    Having a relay in the trailer towing circuit is the proper way to insure you will never drain the TV battery when it is not running.
    2019 320S Sofitel - 2003 Ford Ranger Edge V6
  • GrandmasKidGrandmasKid Member Posts: 159
    I've been struggling with this and am just now seeing that having my lights on might make a difference in my TV output and can't wait to try it tomorrow morning. I have a relay little box on the charge line but I don't really understand it. Can it be thought of as a one way valve for the current flow? We tow with a Toyota Highlander Hybrid and I have been told that they are finicky with their power management and are not really made for towing. We've towed our T@B with it over 22,000 miles over the last two years with great success except for the refrigerator depleting our 92 amp hour AGM battery. The refrigerator on battery, the heater noise at altitude, and the cushions too firm, are the only disappointments with our 2017 T@B Outback so far. Don't get me wrong we are enjoying our T@B after 40 years of tent camping. It is much more comfortable. If anyone has suggestions on any of our issues I'd love to hear them.
     
    2021 400 Boondock/ 2021 Toyota Tacoma Off Road
  • GibWGibW Member Posts: 95
    Another, or perhaps the last, option would be a dc to dc charger. Ours seems to be working now, but I've given these some thought. Here's a link to some at eTrailers.com... https://www.etrailer.com/search/Dc+To+Dc+Battery+Charger

    2017 T@B Max-S, silver & silver, towed by a Titanium Silver 2018 Kia Sorento AWD V-6, Twin Cities MN
  • JEBJEB Member Posts: 266
    This is interesting. I was not aware that turning on the lights might make a difference.  Doing some sleuthing on the Chevy Colorado and its GMC Canyon twin, it does make a difference. There are in fact two ways to increase voltage to the trailer battery when towing with these light trucks: (1) activate tow/haul mode; or (2) turn on the lights if the vehicle has no tow/haul mode or the trailer is too light to use it.  From page 230 of the 2019 Colorado owners manual:

    “To help charge a remote (non-vehicle) battery, press the Tow/ Haul Mode button on the center stack. If the trailer is too light for Tow/Haul Mode, turn on the headlamps to help charge the battery.“
    2019 T@B 400 Boondock Lite
    2019 Chevy Colorado Z71 Duramax
  • CbusguyCbusguy Member Posts: 771
    I put a renogy dc to dc charger on my trailer battery, heavier alternator and ran 2 gage wire to a seperate high amperage anderson connector.      

    Zero problems maintaining a charged trailer battery.

    Luck favors the prepared.
    2009 GMC Canyon,   3.7 liter 
    2020 320s Boondock lite, With Lots of mods
  • RollingBnBRollingBnB Member Posts: 322
    I installed a 200w inverter under the sink so I run the fridge on 120v ac while driving. Works much better than the 12v side of the fridge.
    2020 Tiffin Open Road
    2020 Nissan Versa Toad 
    Alan & Patty
    Southern Az
  • lkc001lkc001 Member Posts: 731
    I have a 2016 Nissan Frontier SV 4x4--I have to run with headlights on or I don't have running lights, brake, or turn signals on my trailer.  At first, I thought I had a wiring problem, but it is just how my specific vehicle is set-up with the tow package.  Other tow vehicles I have owned have not required the headlights to be on when towing.  

    2016 Nissan Frontier SV V6 4x4
    Finally!  New Owner of a 2017 Tab 320S! 
    Woohoo!
  • ScottGScottG Administrator Posts: 5,395
    edited October 2019
    @lkc001, I have the 2015 version of the same truck--I'm pretty sure my headlights don't have to be on for my trailer brake and blinkers to work, but now you've got me wondering so I'm going to double check.
    If that is the case, than something is definitely wired incorrectly, as such a configuration would make for a very dangerous circumstance. There should be no way to disable--even inadvertently--your brake lights and turn signals.
    Do you have the Nissan OEM tow package?
    2015 T@B S
  • ScottGScottG Administrator Posts: 5,395
    UPDATE: Just to be sure I checked this out on my Frontier. While--as expected--the tail and side marker lights are linked to the headlights, the brake and turn signals operate regardless of whether the headlights are on or off.
    2015 T@B S
  • GrandmasKidGrandmasKid Member Posts: 159
    I just read that Toyota Highlander and Camry Hybrids don't have alternators. I just decided to buy a multimeter and a battery booster. I'm determined to get to the bottom of this and be able to boost myself out of camp if necessary.
    "In a hybrid, the engines are off some of the time, the brakes are regenerative, saving pad & rotor life, there is no transmission fluid under load, there are no starters, alternators or belts to be replaced." Mark Jacobson Toyota
    2021 400 Boondock/ 2021 Toyota Tacoma Off Road
  • lkc001lkc001 Member Posts: 731
    @ScottG well, now I am curios--I never knew that

    One of the last things I do before taking off is to turn on the headlights then walk around and  double check tail lights, brakes, turn signals, etc.  Since I found out my headlights had to be on the check tail lights, I just assumed they had to be on for everything else to work as well.  I'll have to check whether my brake and turn signals work without the headlights on.  

    Yes--I have the factory OEM tow package. 
    2016 Nissan Frontier SV V6 4x4
    Finally!  New Owner of a 2017 Tab 320S! 
    Woohoo!
  • ScottGScottG Administrator Posts: 5,395
    edited October 2019
    @lkc001, I do the same thing you do--check everything with headlights on. That's why I didn't want to insist I was correct without actually double-checking.
    I'll bet a nickel yours works the same as mine (also with OEM tow), but if it isn't I would get it corrected ASAP. Realistically, it's just too easy to forget to turn your headlights on every single time you start up and drive off.
    2015 T@B S
  • lkc001lkc001 Member Posts: 731
    edited October 2019
    @ScottG. I will be checking it out this weekend before I move the trailer to it's winter parking spot in the back yard. I didn't know that's how it was supposed to work so I'm sure you are correct. Haven't had any issue at all with my frontier & tows great- plenty of power & absolutely no sway.  I just love my truck 😍
    2016 Nissan Frontier SV V6 4x4
    Finally!  New Owner of a 2017 Tab 320S! 
    Woohoo!
  • WilliamAWilliamA Member Posts: 154
    edited October 2019
    Most, if not all, modern TV's use an isolation relay to control trailer lights. This is because the old school "hook it into the taillight circuit" either dies not provide enough power (amperage) OR the BCM monitors lighting amperage and will set a code if it is too high. The trailer light power relay gets all power for lights on a separate line that goes off with ignition off. If that power supply feed is not on an "ignition on=hot" circuit but rather a "lights on= hot" source, you will not have any trailer lights unless the headlights are on. Either that circuit is misplaced or the BCM is not sensing enough amperage draw to turn it on. 

    WilliamA 
    2021 Jeep Cherokee Trailhawk
    2017 T@G XL
    Can generally be found around west-central Wisconsin.  
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