No Power on 12VDC System

[Molina525]

Hello,

First off, I’ll say that I’ve read numerous threads that reports issues identical to mine, although none of the resolutions on those threads have resolved my issue.

The TT is a 2019 Cherokee 264DBH. My last battery went bad so I replaced it recently with a new one. Before asking, yes it is connected properly. I also checked the two reverse polarity fuses (40A) in the control panel and both are good.

My issue is that nothing works on the 12V system. Not even the tongue jack, which is most annoying when connecting/disconnecting the trailer. I checked all the fuses and breakers on the converter and they are all good. Pictures below are the two power ‘links’ under the trailer near the battery. No button on them to reset like other threads have mentioned. There is a disconnect switch on the battery box and I am getting ~12V when the switch is closed from all of the studs. I did pull off the wires to clean everything up, but I’m still not getting power to the jack. It’s almost like the converter is not switching to the 12V system when shore power is disconnected. Any guidance or ideas are appreciated. Would have troubleshot more today, but ran out of time. Could possibly in the next few days.

[ak49rzrs]

Did you check to see if power is on each post of the "Breakers" (Not a fan of those) And not sure how your set up is, but on my TT the jack is wired directly to the batteries with an inline fuse(is that what the red wire with the red inline fuse is?). With not knowing from your photos which wire is going to where, makes it hard to help.

[wmtire]

Are you absolutely positive there is no little black button on those 12 volt DC circuit breakers? Usually the reset button will be on the end that has the brass colored terminal (not the silver terminal). In your pic there is a bar across the two brass colored terminal lugs. Can you feel under that end and make sure there is no button on the two circuit breakers.

[glen1971]

If everything, including your jack, isn't working, do you have a bad ground? Our jack is fed right off the battery if I remember right.

Did you measure from a ground to your battery positive? 0 volts could indicate a bad ground.

[jimmoore13]

Originally Posted by glen1971

If everything, including your jack, isn't working, do you have a bad ground? Our jack is fed right off the battery if I remember right.

Did you measure from a ground to your battery positive? 0 volts could indicate a bad ground.

X2
That was going to be my hunch.
DC Volts test with the multimeter from the positive battery post to a bare bolt head or similar (say on the power tongue jack). That should be ground if the ground wire is properly connected or you don't have a serious corrosion problem somewhere along the way.

The other recommendations are excellent. Chase them down. But chassis ground (which virtually all RVs rely on) and corroded connectors can be buggers.

[Molina525]

Originally Posted by ak49rzrs

Did you check to see if power is on each post of the "Breakers" (Not a fan of those) And not sure how your set up is, but on my TT the jack is wired directly to the batteries with an inline fuse(is that what the red wire with the red inline fuse is?). With not knowing from your photos which wire is going to where, makes it hard to help.

Thanks for the reply. Yes, I am getting 12V at each of the posts when the battery disconnect is closed. I attached a picture of the wiring with each of the wires labeled to where they run. I forgot to save it on the picture, but the red circled wire that is unlabeled is the trailer brakes cable.

[Molina525]

Originally Posted by wmtire

Are you absolutely positive there is no little black button on those 12 volt DC circuit breakers? Usually the reset button will be on the end that has the brass colored terminal (not the silver terminal). In your pic there is a bar across the two brass colored terminal lugs. Can you feel under that end and make sure there is no button on the two circuit breakers.

Thanks for the reply. I am 99% positive as I pulled both of them off of the frame to clean them up and file down the "bus bar" and check for the reset buttons. I did not see any, but I will double check again when I get the chance.

[Molina525]

Originally Posted by jimmoore13

X2
That was going to be my hunch.
DC Volts test with the multimeter from the positive battery post to a bare bolt head or similar (say on the power tongue jack). That should be ground if the ground wire is properly connected or you don't have a serious corrosion problem somewhere along the way.

The other recommendations are excellent. Chase them down. But chassis ground (which virtually all RVs rely on) and corroded connectors can be buggers.

Originally Posted by glen1971

If everything, including your jack, isn't working, do you have a bad ground? Our jack is fed right off the battery if I remember right.

Did you measure from a ground to your battery positive? 0 volts could indicate a bad ground.

I will double check that. I should have known better to check that because I have had grounds mess with aftermarket fueling systems on my vehicles in the past that a fresh and resecured ground resolved. I will definitely check this, hopefully I'll get a chance to run out to the storage facility this weekend and check for a bad ground. I'll update what I find. Thanks to you both for the suggestion.

[ak49rzrs]

Hopefully you find the gremlin. Keep us posted.

[Molina525]

Sorry for the delayed reply, but I figured out the "issue" with the electrical system. And I feel like a moron.

I went out to the trailer and tested the lighting inside, everything lit up fine. Went out to the battery and checked voltage again - 12.2V. Put a charger on the battery and sure enough, it was only at ~18% charge even though it was a new battery. Charged up the battery and the electric jack works. I had ASSumed the new battery was charged enough, which it wasn't. Must've been sitting long enough to discharge enough to need a charge. Works fine now! Thanks for all the input.

[tomkatb]

Batteries are a pain.

My first step is to test battery voltage. Then voltage with the converter on.

Old British car person. Who, by the way, had never been towed.

Lucas, the prince of darkness, made their batteries and most electrical stuff.