Battery Interconnect Solenoid Always "ON"

[Dan Fessler]

This is my first post as a new Alpine owner and I am still learning so please be as kind as you can. As usual for a newbie I have a problem I can't solve and hope you seasoned veterans can help me.

Background: I have a 2007 Alpine Limited SE with an Xantrex RS3000 inverter/charger with six 6-volt batteries for the house. About halfway (two weeks) into our first extended trip last year we began to experience problems with the HWH system leveling system intermittently not working. It got worse or better. But near the end of the trip it just quit all together. Fortunately, we were close to home. Once back I took the took coach into the local RV shop. They advised my chassis batteries were depleted and the same with two house batteries. Being a good owner and not wanting problems in the future, I had a new set of AGM batteries installed for both the house and chassis. Sure enough everything worked again. I then put the coach in storage, connected to shore power. All was good through the winter months. I checked and started the coach about once a month, and all was fine. Come Spring we had a thunderstorm that apparently tripped the shore power breaker. The AGS had been turned off so the coach was on its own. I was blissfully ignorant of this until I went to the coach about a month later and BOTH the chassis and house batteries were dead, or low enough that nothing worked, and I couldn't start the coach. The chassis batteries did not want to accept a charge or a boost. I finally found a 'fault' light on the Xantrex inverter/charger, so I reset it and enabled the charger. The Xantrex went into "bulk" charge. I left a stand-alone battery charger on the chassis batteries but it hadn't done any good so far so was doubtful. However, a few days later I checked and both the house and chassis batteries showed good voltage recovery. The coach started right up and now everything worked normally in the house. Mmmmm. However, since I had lost both battery banks in a relatively short time off shore power (and they were new), I took the coach back to the repair shop. Now it gets interesting.

Problem: The repair tech, who has been around a while and is somewhat familiar with Alpines found the following:
With ignition off, with dash booster switch completely out of the dash and disconnected, with the ignition switch "off", with NO shore power to the coach, and with all items powered down, the interconnect solenoid is still always "ON" and connecting the house and chassis batteries. The only way to power it off is to physically disconnect a wire. But, if you just touch the wire back on its post, the solenoid clicks and comes on and the batteries are interconnected. Vansco light #19 is on, which from my reading of many posts, means the solenoid is 'on' and the batteries are connected. The solenoid itself is drawing 1.5 amps, but something else (Xantrex?) is drawing 6 amps. That seems more than enough to draw the interconnected batteries down after a relatively short time. There are 5 input wires to the solenoid, three going to ground, one white and one tan. The white and tan wires are paired together and connected to the other side of the solenoid. This is the 'wire' that is always' hot' and powers the solenoid and connects the batteries. The tech doesn't know what is powering the solenoid or why, but he has re-booted the Vansco twice and operated the battery disconnects and nothing changes. Both he and I are stumped.

Question: If you've read this far (doubtful) any ideas?
What powers those input wires and why don't they shut off? Is it the Vansco? (please no) But if so, why would it tell the solenoid to connect the battery banks when there is no shore power and the engine is not running. There is nothing charging!

You are my only hope Obewon.

Dan Fessler
Yakima, WA

[Dsallach]

I’m sure someone with more info than I will chime in soon.
Do you have a wiring diagram for the coach?
Since this is a used coach there is no telling what a previous owner did. On my coach the charger did not charge the coach batteries, only the house. Maybe yours was the same and the previous owner tied the two wires together in an attempt to tie the batteries together in order to have the charger Charge both banks. I would attempt to track the two non ground wires back.

[Ken T.]

I had the same problem an it was caused by a bad Vansco. I did not want to pay the expense of a new Vansco so I made the following changes in my coach


1. Removed the solenoid wire coming from the Vansco output. Added a dash switch that turns on the solenoid (think the Vansco output was a DC return). I use this switch while drivig the rig to connect the battery banks so both are charged by the alternator.
2. Added an echo device which will charge the chassis batteries when the house batteries are fully charged This allows my chassis batteries to charge when using solar power to charge the house batteries.


I have been using this setup for about six year now.

[c_oneil]

You may be looking at changes made by a previous owner. The interconnect solenoid should only have a white wire on one side and a black wire on the other side of the small terminals. Don't understand why you have 5 and none of them should be tan. Is it just a discolored white?
If output #19 is solid on then the Vansco programming is calling for interconnect and closing the solenoid. I don't know why you think that is an internal failure of the Vansco but if you wanted to check you could switch the front and back Vansco boxes and see if it makes a change.

[RVPioneer]

FWIW.

[Dan Fessler]

Thanks you all for responding! It's great to be part of a community. No solution yet. The Vansco does seem to be sending an output message (12v) signal to the solenoid to connect the batteries. But I don't understand how or why. Does anyone know what input readings into the Vansco activate this part of its programming? I figure it must be reading battery power somewhere and somehow, but if the coach is not in a charging state (no shore or Alt power) why would it do that? Does anyone know where the Vansco picks up an input reading about battery status?

I haven't tried the 'Vansco swap' thing yet but may get there and if it is bad then Ken's workaround may be necessary. Dan

[c_oneil]

The Vansco gets 12v off of two ring terminals connected directly to the big house and chassis posts on the back wall of the battery bay. They are both 18 ga red wires with printed marking on the wire. One is BAT-HS and the other is BAT-CH. These wires exit the wire loom and go into the Vansco at the big connector on the lower LH (input side). They are side by side in the middle row of the connector. I can't swear that this is where the Vansco checks voltage to prioritize charging behavior but it sure looks like it to me. If someone has mixed up connections or broken a connection it could confuse the logic programmed into the Vansco. You may want to pull the input connectors off and check for corrosion or damage.

[RVPioneer]

Just walked down to the coach (2005) and opened the breaker to the 50A supply. No shore power, no generator power, inverter off. The rear VMM #19 remained lit.

My understanding is the light is on, indicating the house and chassis batteries are connected, which occurs when both banks are at the same voltage. Perhaps if left without power for a period of time, one set of batteries would see a drop in voltage significant enough to open the relay and disconnect the batteries. If this doesn’t occur, both banks will drain simultaneously.

The schematic shows the VMM being powered from wires connected to the chassis disconnect switch. I’m not certain if these wires also provide a voltage signal to the VMM for the purpose of activating the inter-tie solenoid. The schematic also shows 2 wires attached to the solenoid, but does not show their termination points. The 2007 also has a separate emergency battery connect switch between the chassis and house disconnect switches.

Not sure any of this is helpful, other than the #19 light remaining on while shore power is disconnected. But I do love a good Vansco mystery.

[EngineerMike]

Dan-
1. #19 ON means either front or rear VMM is receiving signal to connect the intertie solenoid.
2. Signals to light #19 are:
a. Boost switch on dash which connects the intertie so you can start off House batt's when chassis batt's are down (or start gen)
b. Chassis batt's are above 13v therefore charging source is active on chassis (usually alternator) and its OK to also charge house
c. House batt's are above 13v therefore charging source is active on house (usually inverter/charger) and its OK to also charge chassis
Of those, 2a is suspect, either switch is stuck if connected, or somebody mucked with wiring, or there is a short to ground inside the switch (output to front VMM is Ground to say light rear VMM #19), or if disconnected the Ground output to the VMM is touching something that is grounded, or ??


The two small posts on later model Alpine's are connected by a wire with a diode inline to minimize arcing when the solenoid snaps open & shut and supposably lengthen the life of the contacts.

[c_oneil]

My understanding of when and why output LED #19 comes on and off is a bit fuzzy but from what I have read in the past RVPioneer has a good grasp on it and certainly Mike too. I do know that without shore/generator/alternator/solar power available at some point of discharge the house bank should be disconnected by the Vansco to prevent total discharge of your chassis batteries. I have also noted there is a time delay programmed in. For example when I first plug into shore power with both banks already at full charge (say from a day of driving) the inverter will start up in bulk charge but #19 doesn't come on for a few minutes. Maybe your house batteries aren't discharged to the point yet that disconnect happens. Your original post says the inverter is drawing 6 amps by itself. That number is about right for the inverter with inverting enabled, plus that 6 amp may include other small phantom draws (like propane detector). How long after the storm and breaker trip did it take to run the batteries down? Maybe a dumb question but do you have that small solar panel that came with the coach still on the roof and working?

[Cinequip]

Dan, I have a 2009 with Vansco, and had issues with #19 LED/solenoid early on in my ownership. Here is what I learned:


#19 is on whenever the battery voltage is above 12.8vdc - regardless of whether you are plugged into shore power or not, or have the genset running. When the battery voltage drops to about 12.8v and below, #19 turns off along with the solenoid. This is to preserve your ability to start the coach, if you run your house batteries down. HOWEVER, the vansco system is powered from the Chassis batteries. Therefore, over a long time (several days or weeks), the Chassis battery will also be drawn down by the Vansco units, even if #19 disconnected the two battery banks correctly.


Therefore, I believe it is entirely possible that you have nothing wrong. In my scenario, here is what I think happened: Shore power fails. Inverter is drawing 6amps. Voltage drops below 12.8v, and #19 goes off, separating the battery banks. Inverter keeps pulling 6amp from house until they are very low and Xantrex system goes into low battery fault mode. Meanwhile, Vansco system is slowly drawing down Chassis batteries until they are low or dead.


Test #19 function on your coach. Unplug from shore power. Turn on lights, fans, etc. and monitor battery voltage. Verify that #19 turns off when voltage is down to 12.7-12.8. If test successful, then you probably are OK, but just suffered a long power outage with all systems operating on battery.

A side note:
As we have all learned (often times the hard way), when leaving the coach off shore power, it's important to disconnect both battery banks with the red rotating knobs in the battery bay. Furthermore, you must turn off the refrigerator and put the Xantrex in Hibernate mode, as both of those will continue to run even with the disconnects turned off.


In cases where the coach is stored on shore power, but where power may be unreliable, I would install a some sort of notification gizmo to alert me in power failure.


I hope this additional bit of information helps you diagnose the issue.

[Janet and Todd]

In addition, make sure the center "keyed" battery switch (the one between the house and chassis disconnect switches) is in the OFF position.

[Dan Fessler]

Thanks for all the thougtful comments, very much appreciated and very informative to me. I have learned a bunch. After digesting this a bit I was close to conclusion that this might be 'normal' state and one of the battery banks was over 12.8 or 13 volts. I can see the 6 amp load from the Inverter drawing down the house batteries over time. But that doesn't explain why the Chassis batteries died at the same time since the interconnect should have disconnected once the batteries dropped below the threshold. That would have preserved the Chassis batteries. Even if my memory of events was wrong and it was two months before I got there and noticed things, a new Chassis battery should have lasted that long. But it was very dead - the Vansco didn't even light up (not even power) until I put a stand alone regular automotive charger on the Chassis battery. That charger really did not do much good even after a couple of days. Then I found the inverter fault and after resetting the inverter I noticed it immediately went into bulk charge. After a day or two of bulk charging everything, including the Chassis battery, came back. To me that tends to indicate that the banks were connected during both the disccharge and during the charging from a low state. I just talked to my tech again with all this new information and he was already ahead of me. He confirmed that disconnecting the Vansco input leads from the positivie House and Chassis banks did turn off Vansco #19. On reconnecting light #19 came on again. But then he wiggled the input plug on the Vansco leads and #19 went off! Exciting!! Except that #19 came back on again a few minutes later. We will focus in on that Vansco input plug and see. but may have to resort to a Vansco swap. I will update when I have more information. Thanks again.

[RVPioneer]

3-4 weeks is a sufficient amount of time for the VMM’s to drain the chassis batteries. The load from the inverter could explain the drained house batteries.

Without being there to monitor the #19 light, there is no way to know if the batteries remained connected. They could have been separated and drained from different loads.

The stand alone charger would have required enough time to charge the chassis batteries before it would have started charging the house batteries.

What is the position of the emergency inter-tie switch that is located between the chassis and house disconnect switches?

Have you placed a load on the inverter, as Scott mentioned, in an effort to lower the voltage on the house batteries to see it the #19 light will go off? This would indicate that the solenoid is open. Then plug in to shore power. Initially #19 should be off while the house batteries are being charged. Once the house batteries reach a specified voltage, ~12.8-13.0, #19 should illuminate, indicating that the solenoid is closed.