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-   -   Intermittent house power (https://www.airforums.com/forums/f240/intermittent-house-power-154535.html)

LB_3 07-30-2016 07:32 PM

Intermittent house power
 
I'm pretty confused. During our drive today IB reported that the house power went out. The battery monitor showed good battery volts and a charging current. Next, she checked the power distribution panel and all the fuses were fine so I assumed it was that the power relay wasn't closing.

We stopped at a Lowes and I purchased some 12ga wire and some alligator clips to jump the coil on the relay. Worst case, if that failed, I would just move all the cables to the same terminal post and bypass the relay. Jumping the relay didn't work so I grabbed a meter and there was only half a volt on the battery side. I checked the battery and all connections were secure.

WTF?!?!? I've got good voltage at the battery and good charging amps from the alternator so I should have good connections between the battery and the battery isolator. We were driving at the time so I could 't check under the driver's seat but presumably both the battery and house loads are on the same terminal of the battery isolator. So I'm assuming those are both good.

Since our LP fridge wasn't running, I jumped the propane isolation valve and pulled the fuse to kill the back current to the other loads (didn't want to start a fire running the entire house from my 12ga jumper). I was just about to tie the fridge into my jumper when the whole house came back up.

Everything is running again but I can't imagine where my open circuit was coming from. Airstream doesn't like sharing their schematics so I'm not sure what is between the battery isolator and the relay. Any thoughts?

InterBlog 07-30-2016 07:54 PM

A bit more detail, which may or may not be relevant to the failure pathway:

At least one other 2007 owner has reported very similar symptoms off-forum, which he attributed to an intermittent failure in the switch that LB_3 was intending to re-jigger on the road today. Knowing this, one of my first actions was to jack with it (off-on-off-on). Doing this re-established power briefly and I was able to turn on one light. But as soon as I triggered the water pump, all was lost again for the better part of two hours. Yet when hubster proceeded to check the line side of that same switch, there was nothing there in terms of juice. That does not make any sense. It could be a coincidence that a brief restoration occurred right when I messed with the switch, but it sorta fails the Occam smell test...

LB_3 07-30-2016 08:07 PM

Oh yeah, my first course of action was to beat on the relay. Given how difficult it was to access the relay, it was really more of a tap than a true calibrated beating.

amirm 07-30-2016 09:45 PM

I don't know what you have for your main relay. But the contactor in my EV Quad went bad. Its spring was no longer functional so all you had to do is entice it to move on its own and it would work. And then not. Mere driving of the Quad would make it work or not. If that is the actual kind of battery disconnect you have, then that could be the problem. What IB is saying would be consistent with this behavior as without the spring, the connection won't be secure enough to pass decent amount of current.

My disconnect is from Blue Seas and uses a rotary control so it would not have that problem. But thought I mention it anyway :).

LB_3 07-31-2016 04:02 AM

Thanks amirm,
I don't think that accounts for the .5 volts to the battery side of the relay. As far as I know there is no other cutoff switch.

Have you made any progress on the Lithium battery install?

Boxster1971 07-31-2016 10:59 AM

Quote:

Originally Posted by LB_3 (Post 1828748)
I'm pretty confused. During our drive today IB reported that the house power went out. The battery monitor showed good battery volts and a charging current. Next, she checked the power distribution panel and all the fuses were fine ......



.... Everything is running again but I can't imagine where my open circuit was coming from. Airstream doesn't like sharing their schematics so I'm not sure what is between the battery isolator and the relay. Any thoughts?


Have you tried contacting Airstream and asking for a copy of the wiring diagrams? I was able to get a partial set for my 2013 model. Also they now include wiring diagrams in the owners manuals since 2015 so you should be able to get a set if you ask politely.


- - Mike
2013 Lounge EXT on 2012 Sprinter

amirm 07-31-2016 12:37 PM

Quote:

Originally Posted by LB_3 (Post 1828809)
Have you made any progress on the Lithium battery install?

Been delayed by shipment of the batteries but they say it is supposed to come this coming week. I have the rest here now and once I get them all on the bench I will report on progress. Thanks a bunch for shining a light in the right direction and motivation to get me to do it. :)

InterBlog 07-31-2016 05:39 PM

I am going to ask politely for the wiring diagrams and this time I will be less inclined to take no for an answer.

Sebtown 07-31-2016 07:23 PM

Interblog, if you can get a copy for your AI and are willing to share it, I'd be
"electrically" grateful

InterBlog 08-04-2016 08:36 AM

Airstream sent me some electrical diagrams. I haven't had a chance to parse them yet to see if they conform to what we think we have, but having them in our possession is a start.

Meanwhile, here's the first leg of our travelogue, if anyone is interested in seeing pics of some outrageously beautiful places.

THE LONGEST JOURNEY, PART 1: HOUSTON, TX TO SYDNEY, NS

InterBlog 10-22-2016 04:08 PM

Postscript to this issue... our existing 12 V has continued to deteriorate and because we are on the cusp of lithium, we haven't put the time into solving this problem directly.

However it got to the point where there were so many power failures that we had to yank the LP detector in the interim - it was screaming constantly.

BTW, someone on a thread recently wondered if they should go with a battery powered LP detector or perhaps it was CO. At any rate, I recommend that T1N owners keep their hard-wired LP detectors. They are the canary in the Interstate coal mine for alerting to incipient electrical issues.

Anyway, I noticed that we only had 12 V off-on-off-on-off-on issues while the engine is running. For that reason, it seemed strongly, strongly likely that the alternator circuit was somehow involved, even though it's not supposed to be able to bring about a condition like that (theoretically). So I asked my husband to isolate the house battery so that it would charge only from the solar. In my view, alternator charging should be elective if substantial solar is in place - it shouldn't be obligatory. Maybe if we had a stretch of terrible weather and poor solar charging, we'd want to involve the alternator. But not always.

Knock wood, everything stabilized after he did this. The LP detector is hooked back up and has made no further complaints. Everything works as designed, with no more cut-outs or die-offs or fluctuations. Over the next few days, I'll get to see if this continues to hold true.

LB_3 10-22-2016 05:07 PM

I disconnected the battery isolator solenoid wires and the issues went away but it's very confusing. The chassis lug always showed greater than 13 volts and the house battery cable and the cable going to the house loads are both on the same lug so it should be impossible for the house voltage to sag down to less than a volt when the chassis battery is connected. I can't wait to rip that stuff out.


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