12 volt issue

[bjhutch]

Hi,
This is my first post, hoping for some insight to get my 12 volt back running!
I have a 1992 13' Casita. I believe the Parallax converter was new when i purchased it in 2016 along with new fuse panel and wiring.
I recently replace the 7 pin wiring all the way back to the inside of the rv. After replacing, I only have 12 volt function when plugged in to the tow vehicle with 7 pin. No 12 volt on shore power or on battery power, only when plugged in with 7 pin.
Converter is getting 120 to all breakers.
With the polarity fuses removed and plugged into shore power, there is 13.8 volts between the blue and the black main connection on the converter dc . Battery reads 13.8 at terminals.
All fuses replaced. Traced wires and no inline fuses found.
Battery and converter ground separately to frame, BUT were recently painted over when painting frame, not sure if that's my issue. Any help is appreciated!

Thank you!

[Casita Greg]

First, welcome to the forum.

I guess my first question would be how old is your trailer's battery? As a general rule, Lead-Acid batteries only last for roughly about 5 years. I would recommend pulling the battery and taking to your local auto-parts store and have them" load check" it on the bench. Generally, they will do this for free as a service. Just a good place to start your troubleshooting. If the battery is kaput, then nothing else will make your charging circuit work.

And as to the paint on the frame and grounding terminals , well, I'll just say that it shouldn't be painted. You may want to also clean the frame and terminals to bare metal where your ground wires are attached to assure a good clean contact surface.

(And don't forget to reinstall your polarity fuses if you haven't already. Without them, there will be no charging current going to the battery.)

[Jon MB]

Since there is no 12 VDC when on shore power, power that would also be present with the battery removed, I'm not inclined to suspect the battery,...yet.
It could be the converter has failed and can't make 12 VDC, and the battery has run flat because it hasn't been re-charged from the dead low voltage side of the converter.

[Lynn Eberhardt]

Since everything works when the 7 pin is connected, painting over the frame ground connection is probably not the problem. I would suspect a missing or bad connection between the newly installed 7 pin wiring and the trailer battery/converter wiring.

Test: Unplug shore power. Check trailer battery voltage. Connect tow vehicle and start engine. Battery voltage should rise. If it doesn't, you'll know that a connection between the two is missing. If it does go up, I have no idea what's wrong.

[bjhutch]

Thank you all for the replies!

I had the battery checked and load tested and it is good. I believe it's only a little over a year old, deep cycle Interstate marine battery.

I will check the steps recommended by Lynn and see how it goes.

If that doesn't reveal the issue, I will once again follow the wires and see if I'm missing an inline fuse. And i'm redoing both grounds and removing the paint just because i probably should.

Thanks for the suggestions, I will repost when i know more!

[bjhutch]

Hi,

I disconnected shore power. Trailer battery voltage at terminal is 13.46. Plugged in 7 pin and started tow vehicle, voltage at trailer battery stayed the same. I will try and locate a bad or missing connection between 7 pin and battery/converter.

Thanks for all suggestions! I will continue to problem solve!

[Lynn Eberhardt]

Your initial comments, along with your test results, indicate that your tow vehicle wiring is good but your trailer battery will not charge while towing. Good luck finding the problem.

[Ruth C.]

The easiest solution would be to let me take that baby off your hands. I’ve had a Scamp 16’ and two Casita 17’s, but a Patriot has been my dream, my unicorn, my white whale.
You’ll never have to worry about its electricity again.👍🏻

[Yardsailor]

From what you have posted the problem is a break between your battery and fusebox. Test outward from battery until you get no power. To determine whether break is on positive side or negative side leave one side of meter at negative at battery and test outward, then do the same leaving positive test lead at battery and test outward.

[pete_britt]

Many of us have had to replace a Parallax converter. I would check it first.