2009 keystone cougar electrical issues possibly?

[Katiestar]

We recently got a 2009 keystone cougar and living in it full time. 1st issue was leaking water heater, we replaced that with a tankless one off Amazon and worked great for many months now. Then that freezing temps happened. And started showing FD code. Found out that the pump completely froze, so we replaced that. When you turn pump on now, it short cycles the battery ( lights flicker, and gradually the battery goes down). Also, we are plugged into shore power but not city water. So we went ahead and bought a converter. Same problem. Now it doesn’t even work enough to trigger the FD code on the water heater. We insulated and bought one of the pad heaters to put on fresh tank but haven’t yet as we are still just trying to get the pump to work without draining the battery. What should we check next? What could be the issue?

 

[workinonit]

Who installed and wired the pump? If the pump is not running when you turn it on and drains the battery it could be that the pump got wired backwards. I'm not sure what an FD code on a tankless heater is but with no water flow you are going to get a code. It would be a help if you posted some info about what components you bought and who replaced them.

 

[JRTJH]

Also, is your battery still connected, even though you're on shore power ????

It "normally should be connected" but in your situation, with the freezing temperatures and issues with the converter, pump, water heater, during all that "repair and replacement of parts" your battery may have been discharged and if so, it may have frozen, causing PErMANENT INTERNAL DAMAGE to the battery. If that happened, it would explain why the lights dim, the pump doesn't work and the water heater won't ignite.... If the battery has a shorted cell, it will pull down the converter, preventing it from delivering adequate voltage to the trailer, even on shore power....

So, disconnect the battery, isolate the terminals so they won't short out, plug the trailer into shore power and see what you get.... If it works properly and the pump and water heater start working, then it's the battery damage causing the current problems....

That said, DO NOT OPERATE THE SLIDES (if you have any) WITHOUT A BATTERY !!!!!

 

[Katiestar]

Yes it’s wired correctly

My husband installed it. The pump turns on and runs it just drains the battery and the pressure isn’t great. Unfortunately it’s not enough pressure to kick on the water heater. My husband is an automotive mechanic and also used his power probe. When the pump is on and running the converter is still operating as it should but the battery is still draining. If I turn the pump off battery goes back up to full. Also it only drains the battery when the faucet is on. He said it’s almost as if there is a leak somewhere except we can’t find any water anywhere

 

[JRTJH]

Tell him to disconnect the battery and load test it. If it's good, tell him to locate the converter charger and check the two fuses on the end of the converter/charger to make sure they are good. If it's not the battery, then next place would be the reverse polarity fuses on the converter/charger.

 

[Katiestar]

Will do

I will ask him to do that here shortly but out of curiosity if the converter is new, shouldn’t the fuses theoretically be new also (I know some things can just be faulty from manufacturer).

 

[JRTJH]

It's not a matter of the converter/charger being new or not. There are two "reverse polarity fuses" on the converter. They "blow immediately" if there is any reverse polarity on the battery cables. If, for instance, the POS cable happened to contact the NEG battery terminal and produce a spark, that "instantaneous spark" is enough to blow the reverse polarity fuses. That action (blown fuse) will disconnect the battery from the converter and stop all charging. When that happens, the battery will drain down and the lights start dimming until they stop working. Then, if you disconnect the load (turn the lights off) the battery will recover slightly, and the next time you turn on a light, it will work and start going dim again until it stops working.

A battery with a damaged cell or a shorted cell (like from freezing while discharged) will act the same way...

From what you're describing, either of those conditions, a bad battery and/or a blown reverse polarity fuse will cause the symptoms you're describing.

As a note, when replacing the battery, it's very easy to blow the reverse polarity fuses while connecting the battery. Now, the battery cables that connect to the converter/charger are the other end of that same cable/same circuit, and it's just as easy to connect the converter/charger (even a new one that you're replacing) and cause the same condition with the cables which will "instantly blow the reverse polarity fuses"....

As a general rule, if, after replacing a battery or replacing a converter/charger and I have any kind of electrical issue with low voltage, dead battery, dimming lights or such, the first thing I do is check those reverse polarity fuses.... Doesn't matter if they are new or not, their function is to open when necessary and while connecting either end of the cables is an ideal time to produce that spark that blows a reverse polarity fuse.....