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Tiggs's avatar
Tiggs
Explorer
Sep 30, 2013

Batteries not getting 13.6 volts from distribution center

I hope someone will be able to provide me with direction. I noticed my batteries were not holding their charge so I started investigating the problem.

I started by checking the inline fuse on the black/positive wire. It was fine.

I started troubleshooting the distributor center as suggested by the manual, first by checking the two reverse polarity fuses which were fine. Next, with the trailer plugged into 120V AC, I unhooked the battery cables from the battery distribution center and tested the voltage at the battery cable ends. It read 0.00. I went in and tested the positive and negative output lugs and it was 13.6 (as the manual said it should be. Am I wrong in assuming the distribution center itself is working properly?

I've swapped out the inline fuse just to make sure it wasn't causing a problem. If there is an open in the wire, how would I find it? The wires travel down the frame of the RV for only a few feet and then disappear into the underbelly. How doI check for a loose ground? Finally the manual says it could be improper torques. What the heck does that mean??

Now comes the wacka-doodle portion of my question. Yesterday I could not get my trailer's clearance lights and license plate light to come on. I found I'd get a flash of lights if I smacked the left rear brake light so I took the lens cover off. As I worked, the clearance lights flickered on and off. I reached behind the brake light LED and pulled the bulb for the license plate light and the flickering stopped and my clearance lights came on and stayed on. I've got the bulb pulled out so I can get a new one. There is no freak of RV wiring that would cause these two issues to be related, is there? And why would a bad license plate bulb cause the clearance lights to go out?

Sorry for the long post, guys. Thanks for any insight you are able to give me.

Carolyn

17 Replies

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  • BFL13's avatar
    BFL13
    Explorer II
    Sep 30, 2013
    Got lost where you disconnected the battery at the DC dist panel and got no voltage instead of converter voltage at 13.x. with shore power on.

    Usually you disconnect the battery wires at the battery itself.

    I know what you mean! :( It might make more sense in the morning.
  • Tiggs's avatar
    Tiggs
    Explorer
    Sep 30, 2013
    I've already checked the reverse polarity fuses The inline fuse is fine and the batteries were providing power to the cabin. I don't understand how I can be sending 13.6 from the distribution center and not having it get there when the battery is sending power up those same cables to the distribution center and powering the lights. I'm going to have to re-verify everything tomorrow. I've got the batteries disconnected from the TT and am charging them with a car charger right now. Maybe there is something really stupid I'm forgetting? I was getting dark and I was a bit tired when I was trying to figure this all out.

    Carolyn
  • enblethen's avatar
    enblethen
    Nomad
    Sep 30, 2013
    You have two problems.
    Would help to know what kind of rig.
    Have you tried cycling your battery disconnect switch, if equipped. Turn off batteries then back on.
    Some rigs have another circuit breaker or fuse adjacent to the batteries.
  • tenbear's avatar
    tenbear
    Explorer
    Sep 30, 2013
    IMHO, I think the battery charging and the lights are unrelated problems, but possibly not. I suspect the lights is a ground problem. Measure the voltage, or use a test lamp, using a separate ground.

    If the wire from the distribution panel and the converter to the battery is good, maybe that is a ground problem, either at the converter or the battery.

    BTW, is this a TT, smallish MH or a DP?
  • BFL13's avatar
    BFL13
    Explorer II
    Sep 30, 2013
    At the 12v fuse panel, where the battery wire lugs are, the battery and converter go to the same lugs (back and front), which then supply the fuses to the various 12v circuits.

    OK, so you got 13.6 there which means the converter is ok on shore power. Now disconnect shore power and any 7-pin connection. You should see 12.x from battery at those lugs.

    You say you got zero but you might have also disconnected the converter, don't know.

    You have a battery disconnect switch somewhere, and then closer to the battery, a fuse (or DC circuit breaker) at the pos wire on the battery (might be on the neg ) to check out too.
  • RoyB's avatar
    RoyB
    Explorer II
    Sep 30, 2013
    Check your distribution center for usually two FUSES that are off to them self labeled REVERSE POLARITY. These are two fuses along with the single in-line fuse you have already checked that are between the 12VDC distribution panel and the battery terminals.

    The batteries should also power up your inside ceiling lights when you are not using the 120VAC shore power connection. i.e.if you are disconnected from the shore power connection you should see the 12.6VDC coming from the charged up batteries at the same point where you measures the 13.6VDC when you had the converter activated.

    If you don't see the battery DC voltage at the 12VDC distribution panel then you have blown fuses, bad connections, dead battery, or perhaps an installed battery disconnect switch in the OFF position.

    Has any work just recently been done on the battery terminal which was removed. They may have been installed in REVERSE ORDER. Find the word "NEG" or the symbol "-" on the battery case and make sure the cable connected to this negative battery terminal post comes from a FRAME GROUND connection which should be close to the installed battery. This is about the only thing that blow the REVERSE POLARITY fuses.

    Roy Ken

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