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qhumberd
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WFCO with cold solder joint?

californication
californication Member Posts: 46
in Battery/Electrical & Solar
One morning I noticed that my trailer has no power. 
Currently the trailer is arked at my parking spot, so it was not the problem. I went to inspect it, and I immediately checked batteries -- they were fully charged. Next I looked at fuses. When I touched second from the bottom fuse, the trailer came back to life.
I left the trailer "on" and today I saw it being 'dark' again. The same scenario repeated. It was enough to just touch the second to last fuse to get it back running.

Did anybody experience anything similar? Is it possible something got loose from cold weather. I'm in CA, temps are above 32F up to 70F right now during a day.
Tab 320s Boondock 2022 | Jeep JKU 2017
Mods: MaxxAir 7500S | 2x 100Ah LiFePo4 | Victron Orion-TR DC/DC | Victron MPPT 75/15 | Ultimate Trailer Jack
2024: 7,949 miles; 76 days; OR, CA, NV, UT
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Comments

  • pthomas745
    pthomas745 Administrator, Moderator Posts: 4,527
    In my 2017, those two "bottom fuses" are a 30 amp "battery charging" fuse and a 40 amp "battery protection" fuse.  The "battery charging" fuse (I'm guessing a bit here)  prevents a surge of power from being sent to a battery in a very low state of charge.  You don't see these blow very often, though.  
    I suppose it is possible for a fuse to get loose in the little metal "bracket" it fits in.  Have you pulled that fuse and had a look at it?
    2017 Outback
    Towed by 2014 Touareg TDi
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  • Grumpy_G
    Grumpy_G Member Posts: 710
    edited February 3
    pthomas745 said:
      The "battery charging" fuse (I'm guessing a bit here)  prevents a surge of power from being sent to a battery in a very low state of charge.  
    Generally speaking, fuses protect wiring so this fuse is supposed to open when there is a short in the wiring between the power center and the battery. However modern LiFePo batteries with 50+ amps of charging current can easily max out the converter and draw more current than the fuse (and the wiring) is rated for.  Typically there is also is a circuit breaker or fuse near the battery for the same purpose, the circuit is somewhat unique in that it does have power sources at both ends. 
    As for a cold solder joint, anything is possible but I I'd think it's not likely. Rather have a really close look at the fuses, or just replace it and check that the contact is tight and not oxidized. 
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  • californication
    californication Member Posts: 46
    No idea what happened 2 weeks ago, but currently everything seems to be fine. I'm still monitoring that.
    Tab 320s Boondock 2022 | Jeep JKU 2017
    Mods: MaxxAir 7500S | 2x 100Ah LiFePo4 | Victron Orion-TR DC/DC | Victron MPPT 75/15 | Ultimate Trailer Jack
    2024: 7,949 miles; 76 days; OR, CA, NV, UT
    · Share on FacebookShare on Twitter Share on Google+

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