No DC from Converter

jquarles · 09-13-2013, 06:59 PM

Hi all,

It's been a long time since I have posted because my TM has been doing great. Well, now it isn't. I believe this to be total user error and not TM. But I am hoping some of the great minds here can help me troubleshoot.

Very long story, but trying to give enough detail and background.

I have a 3326 with dual 6Vs. These have always been great since I always boondock. Coming out of winter, before my first spring trip I check the water in the batteries since I have been sitting on a trickle charger through the winter. Water was good but I topped it off a little. I went on four 4 and 5 day trips and the batteries held up great. On day two the of the last trip, batteries died and had to borrow a genny to charge it up. I thought, maybe I didn't charge up the batteries fully before I left on the trip (should've been my first indicator). Last day packed up, switched the fridge to battery, connected the tow vehicle and drove home. This is the same method I have been doing for years.

Got home late and knew I didn't have to work the next day so I didn't need to unpack everything. This is the beginning of my downfall. Course I know this all now in hindsight. 1) I forgot to turn the fridge off of battery even though we unloaded it, 2) forgot to plug the trailer in to shore power and 3) left it plugged into the tow vehicle.

The next morning I discovered my tow vehicle doors wouldn't open via remote....dead battery. Next I hear the loud beep from the trailer....dead batteries. So, I unplug the trailer from the tow vehicle and plug the trailer in to shore power and wait a couple of hours. Go back and jump in the trailer. Same dead battery loud beep and when I press the battery test on the panel in the trailer it still shows no DC even though I am connected to shore. I check the fuse panel and both 30 amp main fuses were blown. I checked the rest and they were fine. I replaced the fuses from my spares and checked the panel. Still no DC. I unplug the trailer and start checking around. I find that both batteries have no water I can see....crap. I fill them. Check all the breakers again. check the fuses again. make sure all the wiring to the battery terminals are clean and tight. Plug it back in. Still no DC showing even though I am on shore power. Now I hear clicking... Search the trailer and the clicking is coming from that metal fuse/relay/battery isolator thing mounted inline about six inches from the battery post. I unplug the trailer and search the internet for what to do. Read that the little relay could get too hot and stop working. After about an hour I go back and plug it in. No more clicking sound, but still no DC power and the test button on the panel still says no DC. NOTE: the AC devices work. The air conditioner and the microwave.

So my last ditch effort was that I read that if the batteries get too dead, the converter won't charge them and things don't work. I unplugged the trailer and I got the trickle charger out and charged the battery up. Let it go two days. Test Panel was lit all the way up. DC lights running fine. I leave some lights on for 12 hours to let the battery drain some. It drained more that normal. But in this halfway state I could then see if I plugged it back in to shore power without a totally dead battery, would I get full DC. (testing the internet theory). Nope. Still no DC from being plugged into to shore power.

So this is where I am and here is what I still don't know.

Is the converter broken so it won't send power to DC when I am on AC shore power
Did I ruin my batteries and they can't hold good charge now?
Could that battery Isolator be causing this?
And finally, is it a combination of any of them?

Hope some readers made it through reading all of that. I tried to be comprehensive enough so that you wouldn't have to play 20 questions in order to get the data you need to help me troubleshoot.

Any help would GREATLY be appreciated.

John

TrailManorMan · 09-13-2013, 09:25 PM

Thinking1&2 may apply, once had a similar problem and it was converter.
Not too difficult to change out other than laying on floor.

Batteries that dead may have "stressed the converter" hope not.

Redtail Cruiser · 09-13-2013, 10:26 PM

Hi John,

Welcome back! We could guess what your problem is, but your best bet is to get yourself a good multi-meter or just a simple DC voltage tester will do. Start with your batteries, then move to your converter and see whats what. Let us know what your readings are. Then we will have a better chance of diagnosis, but if your batteries are damaged or dead you'll have to replace them. If your converter is damaged, you might be better taking your rig to an auto-electric shop or RV shop and have them check it out. Might be an easy repair and cheaper than replacing the unit. If the converter is fried you'll have to replace it yourself or have it them do it for you.

scrubjaysnest · 09-14-2013, 05:57 AM

First thing I'd do is disconnect the plus lead from the converter to the batteries. Plug in the shore power and see if you have 12 volts at the converter. Unless you have a non-standard converter you should be able to run a 12 volt light from the converter in this manor. This will tell you if the converter is good or bad. There are a couple of threads on the site on how to change it out if bad.

09-14-2013, 08:15 AM

I would also pull the batteries and have a dealer check them. If you drained them to zero and then charged them enough to boil out the water, you may have shorts. The battery can appear charged when on the charger, but be unable to support a load. The convertor may just be seeing an over current situation and cutting off. If you have another 12V automotive type battery, connect that to the convertor to check it.

jquarles · 09-14-2013, 02:10 PM

Thank you for all the replies. I am going through the list of things to try

"First thing I'd do is disconnect the plus lead from the converter to the batteries. Plug in the shore power and see if you have 12 volts at the converter"

I disconnected the plus lead. Plugged in shore powere. Not a thing showing on the test panel. not even the light to show it is dead. But the Microwave and the Aircon are working . So AC is not getting to the DC side.

Next I wil try the extra battery