House side electrical issue - 2004 Vectra

[emiddleb]

Looking for some thoughts on what to check next.. 2004 Vectra 40KD.

Problem - only about 1/2 of my OnePlace monitors are working, along with a couple other things related to the panel switches.

Working - the Dimensions inverter panel works, as does the holding tanks display. The battery display works for the engine batteries. Finally, the gen switch/display works.

Dead - Powerline EMS display, the water pump and both the gas and electric water heater switch lights. The water pump and water heater gas side does not work, not sure on the electric side. Finally, the House battery side of the battery display does not work.

Cause - I found one of the 12v 15amp resettable fuses on my bedroom panel had popped out... marked "Monitor/TV." Reset the fuse, everything working!

About 15 seconds later, the same fuse popped again. Tried with and without shore power, no difference. Fuse still pops after 15 secs (approx.)

Figuring start with simple fix, I ordered a new 15amp fuse. Installed, same problem. Works at first but after 15 seconds it pops.

Now I'm stuck where to go next. It's not the fuse since that was replaced. I'm thinking (and may be wrong) that since the fuse doesn't pop instantly but takes 15 secs that it's probably not a true short in the wiring but something is drawing too much voltage. Correct?

For grins, I tried turning off several of the 120v breakers (water heater, A/C, etc but no impact... 12v breaker still pops. For what it's worth, everything else seems ok. The Dimensions panel indicates all is ok there. All 120v items appear to be fine. Other 12v items (lights etc) seem ok. During the 15 seconds before the fuse pops the non-working items on the panel (Powerline EMS, pump, water heater switches) all appear to be working fine with no issues indicated.

If you made it this far, thanks for reading. Wanted to give all the data I could. Any thoughts on further diagnostics, things to check, etc?

 

[Morich]

Good job on trying to get all the info needed to help sort the question! Unless there is some major shortage of digital data, I hate posts that don't tell us anything! What I would expect is not likely to involve the 110AC side of things but likely a short in the 12V coach side of things. Shorts come in different levels for blowing the fuse fast or they can be less solid shorts and it takes longer for the fuse to heat to melting!
The trick then becomes finding which portion of the circuit that fuse feeds is "leaking" or shorting to draw too much current.
Kind of like at the house and the water bill gets too high and you shut it off? You have to find the leak!

It sound like some of the wiring behind the monitor panel may be shorting. No work been done in that area lately? Maybe just some bundle of wires hanging down and swinging around has rubbed something bare?
Give me a bit to find some info and we might be able to point where to check?

 

[powercat_ras]

Since your RV is 2004, the full electrical diagrams are downloadable from Winnebago, so you should be able to see all the things that are fed by that 15 amp circuit breaker and use that for troubleshooting.

FYI, the 12 volt and 120 volt wiring and devices is totally separated, except for a 120 VAC to 12 VDC converter charger function and a 12 VDC to 120 VAC inverter function. These may be in one unit a "Magnum" in your particular RV. There is nothing specific to a single 12 VDC branch circuit with these functions.

Playing with 120 volt things should make no change to your 12 volt branch circuit specific problems and the 12 volt branch circuit breaker doing it's overload trip.

You'll want to be very observant of fire indications until you find and fix the problem as there is a major 12 volt fault, generaly that fault current is turning into 100s of watts of heat somewhere and could potentially could ignite a fire.
The fact that the breaker trips in a few seconds is probally saving you from that.

Do not bypass the circuit breaker or try to fix the problem by putting in a larger one!

 

[Morich]

GULP!
I found that fuse and circuit but the problem is that it does so much! I was thinking monitor panel and that put it in that wiring but then when looking it also feeds many, many other items that connect at the monitor panel!
That makes looking for where the short ight be much harder as it goes to so many different things at different locations on the RV.
Looking in a 40 foot field instead of a 2 foot wide one?

So maybe some questions? Can I assume that with the fuse out, there is no water pump working?
Let me verify that I'm looking at the correct fuse to get the correct circuit ID!
click this snip for better view!

Top is the front and then when we turn it around to look at the back the fuse at top right becomes the top left?
Assuming I have the right fuse, we use the back side of the drawing to find what circuit that feeds and it shows us JP being that circuit!
We have a chart to "decode" the ID on wires and drawings.
https://www.winnebago.com/Files/Files/Winnebago/Resources/Diagram/electrical_guide.pdf

Looking down to JA it tells us some of where that circuit goes and what it might do. JA is power to a BUNCH of stuff! That also tells us the ground is JP!

The problem with finding where that circuit is shorting and current running to ground is that it goes so many different places.
Hoping to cut the chase a bunch, I was thinking of the water pump area as a place where we may have activity that might damage wiring.
Any chance you have something stored near any of the water pump wiring that may have slid or moved to damage that wiring. Either near the pump or near any of the water pump switches?
My tool box is one that tends to slide around when we drive!
If you can think of when this started and what may have happened, it may save a ton of trouble as that circuit goes all over the RV almost!

A lot of those circuits do come together at the monitor but I hesitate to mention pulling that out as a random place to look, without trying to look at easier points!
If you can spot something that might slam a water pump wire or switch, that might be the best ending for this story as it gets tricky to look at all the other things involved! :whistling:

 

[Morich]

I spotted a second point that might be suspect?
Do you have a smallish monitor panel in/near the wet bay where there might be a problem show up?


Nothing simple like it got sprayed with water in the wet bay?
Just hoping!

 

[cbeierl]

Here's my response in reply to your duplicate post on iRV2: House side electrical issue - 2004 Vectra

 

[emiddleb]

Thanks to all for taking the time to read my novel. As I suspected, no short/easy fix but time to start narrowing down the possibilities.

Just a couple of responses to various questions...

Yes, with the circuit popped the water pump does not work. When reset, it does work until the breaker pops again.

The only reason I tried the 120v stuff was to just eliminate anything related as an issue, like the 120v side of the water heater or an issue with the Dimensions inverter/converter. Didn't really expect it to make a difference but by testing with and without shore power I was able to rule that out. Just covering all bases.

No, I'm crazy but not stupid <g> and never considered replacing the 15amp with a heavier breaker. Agreed that the popped breaker is saving me from a bigger problem!

Unfortunately, nothing specific changed/occurred when this started. Had returned from a trip (all fine) and parked the RV in my garage. Went out a few days later and found the issue. No maintenance or repairs done.

I do have the small tank display monitor in my wet bay.

I do have the wiring diagrams for the coach, but frankly with my skill set I find them almost useless. Just me... there's a load of info there but understanding it is not my forte.

I'm thinking that I'll start out there in the wet bay where the water pump and monitor panel are located. Failing there, guess I'll start looking in the rat's nest behind the OnePlace panel. Been in there before, years ago.. it's a mess.

Thanks again to all for your thoughtful responses. I'll let you know if/when I discover the issue. At least now I know what breaker feeds power to many of the OnePlace controls!

 

[cbeierl]

Do read my reply in your other iRV2 thread.

 

[powercat_ras]

2004 Vectra/Horizon S40KD Wiring Diagram Book

I'm a retired electrical engineer and have been working with Winnebago drawings for my RV and friend's RVs for about 15 years.

Looking at the wiring diagram and going by your description of the problem it looks like the circuit giving you the problem feeds yellow wires that have JA stamped on them.

Unfortunately the diagram does not show JA transitions from being one 12 gauge wire coming off the back of the circuit breaker in to the multiple 14 gauge wires. I suspect there is one or more insulated splice in the wiring harness somewhere, and there is also one or more insulated splice in a ceiling wiring somewhere. There is another drawing called Wiring Installation that will show how the wiring harnesses are routed but will not show where the splice is.


You can find all the places that JA feeds starting from Sheet 2 of the drawing, I see:
- connector feeding external radio
- water heater on/off switch
- water pump switch, probably the one near the water heater switch
- load shedder control board located in 120 V Panel (breaker box?)
- monitor panel
- exterior monitor panel
- to a 15 pin connector that ties to a harness in the roof,
located behind bedroom TV ...
The harness in the roof's JA goes to 4 connectors for Sat stuff

=====

If this were my RV and I was working this problem, I'd start unplugging all the connectors with JA in them and see if the breaker still trips. If breaker still trips with all the destination connectors unplugged, the best step forward IMHO would be to abandon the factory JA wire and run a new one from the circuit breaker to the things fed by JA that still work and that you need need such as the monitor panels, water heater switch, water pump switch, load shed board and just leave the rest disconnected.

Note: JA only feeds power into the "first" water pump switch then the water pump power feeds from that one thru the others and from the "last" one in the string to the water pump, so you only have to worry about disconnecting JA on that "first" water pump switch.k

Good luck.

 

[Morich]

I would never recommend testing a short by putting the power fuse back to see if it arcs again!
Each time something arcs it burns the connection a bit more. If the connection is at a circuit board, you are quite possibly working on ruining that board! If it is a wire rubbed on a metal fame part, you are just going to make the insulation melt a bit more each time.
You are not really improving the problem if you keep repeating the failure!

That's kind of like hitting yourself with a hammer and finding out it hurts. Do you want to keep doing it until it doesn't hurt? Most folks figure out they need to move their finger first!

 

[Bobn1957]

Disconnecting things one at a time is a good way to diagnose the problem, I would disconnect the pump first as it is the biggest draw on the circuit!

 

[emiddleb]

Well, the hunt still continues. Still have the fuse-blowing issue.

At this point I've tried (as suggested) disconnecting one thing at a time to see if anything helps, while also examining the wiring as much as I can for each item...

1) disconnected the water pump power in the bay

2) disconnected the tank monitor display in the outside water bay

3) disconnected the entertainment bay radio/tv 12v power

I have also pulled out the OnePlace display panel and generally inspected the wiring rat's nest to see if anything obvious stood out. Also gently pulled/tugged on the rat's nest to see if anything changed... no.

I've also verified, as best I can, that during the 10-15 seconds before the fuse pops, everything seems to be working normally... water heater electric switch lights up, water pump runs, house and coach battery levels show up in the display, and all tank level lights work. Then 'pop'. Interestingly, the interior tank monitor display still works when the fuse pops. The bay monitor does not.

Next will be trying to unplug the associated cables behind the bedroom TV (a bugger to reach) and then the load shedder controller board in the 120V panel.

 

[Morich]

Yes, this is going to be a real problem to find and it will take the correct approach, not the one you are using!
As you've found, it takes a bit to really think and test each item but you don't get that time if you are using the fuse as a test! It blows way too quick for you to think!

What if you changed the idea of what to use for the testing? Meters are meant to test and they don't blow up every time you take too long!

There are numerous items connected to that fuse. Some are the equipment and some are just the simple wires feeding those.
It is not rational to think you will be able to see the problem but a meter can test for it and let you know where to look. It may be some item that has failed or it may be a defect in some wire.

Think of what the fuse is telling you when it blows. It is telling you there is way too much current moving from that circuit to ground! That can be called a short, short hand for short circuit!

If you disconnect that circuit from the power, like maybe take the fuse out, then you can look at the wire for that circuit with a meter.
If you see a short to ground (likely!) then you can move through the circuit and find what is causing that short!

There will be a variety of things that DO show up as a short making it necessary to go to those and disconnect them until you get down to where the fault might be.

Unfortunately, Circuit JA is one of the main power feeds to lots of different things but that is just a common problem when we have a large number of items on one circuit!
The problem is then finding WHICH part of which leg of that circuit is a failure versus the normal reading we would see from things like lights or motors.

The monitor panel may be a high level suspect as it has lots of stuff prone to breaking down connected to it. So if you have it out, now sounds like a good time to look for any short and isolate it to being beyond the monitor, before the monitor, or not even anything involved with the monitor!

If you look at JA when it is disconnected from power and see a short with the monitor connected but the short is gone when the monitor is disconnected, you can then move to the monitor and try to find what item connected to the monitor has failed or if the monitor itself is the fault.

I might suggest disconnecting the monitor panel inside, if already open as there is a 15 pin connector that has JA on it. Logic says that the more connections, the better the odds of the fault being beyond that point!
If the meter still shows a short, perhaps move to the exterior monitor panel and disconnect the 9 pin plug there.
You may get lucky and find the short on the first plug or it may take disconnecting a whole bunch of things but if you do it in a well thought out way, you should find the meter shows the short is gone when you disconnect some item.
The trick them will be to further isolate the problem.
Is it the wiring going to some item or is it the item itself? Let the meter guide you!

It may be a difficult as the monitor has failed or as simple as some item slid around in a compartment and banged into the light switch!

 

[rjadams]

Robert

I have a 2012 26p Vista. The bulb for the inside hot water electric switch is burned out.
Does anybody know how to get that switch off the inside wall to replace the bulb?
Thanks

 

[emiddleb]

Semi-success!!

After a ton of work, I have determined that it's the Powerline EMS shedder circuit board in the 120v breaker box or the associated wiring. When I disconnected the 12v connection to the board (8 pin) the problem breaker did not pop. So the EMS function/display is disabled, but all other stuff on the JA line (water pump, tank monitors etc) are working fine.

Will still have to figure out if it's the board or associated wiring, but at least determined the core issue and have functionality back on the rest.

Thanks again to all for helping me find the problem.

 

[Morich]

Sounds like you are homing in on the problem and that info gives me some further ideas?
You have a 12Volt DC fuse feeding power to circuit JA which blows when the load shedder is connected to the 12Volt?? I was not aware of 12vdc connection to load shedder! Maybe one of those secrets that leave off the drawings or maybe I've not gotten around to spotting it!
The primary function of the load shed is to remove some of the 110AC load when too much load. But it is not the 110 that blows but the 12VDC!

So if we look at the load shedder and what involves 12Volt as well as 110AC, the water heater seems to come up as suspect!
Click these snips for what I'm thinking?
Load shed is mostly 110AC but there are some items which may also involve the 12VDC (JA) that blows!

There is a direct connection to circuit JA and the water heater as this snip shows.

Power comes in from JA to the water heater switch and lights the indicator light before going to ground. But at the same time that power is connected to a four pin connector at the water heater, shown as wire HHJ!
Can you get to that four pin connector to remove it to see if the short is then removed?

It could be problem with the switch or at the water heater but seems easier to remove the plug if it is where you can find and reach it! The switch may be soldered?

Just thinking ahead for when you get around to it!
I'm resting easy here on this end! My end gets lots of rest most days!

 

[emiddleb]

Thanks Richard.

I've attached the Powerline EMS manual, which has all the wiring info. FYI, I'm the 50amp setup.

Looking at the doc, I'm not seeing much about the water heater, but the 8-pin connector that appears to be the issue is associated with the AC. I have the basement central AC/heat pump and I believe the wiring is associated with the two fans and compressors on the basement AC.

I'll try to locate that 4pin water heater connection and see what happens when I disconnect the water heater 4-pin and reconnect the EMS 8-pin.

At the moment, with the 8pin disconnected on the EMS board, the water heater switch appears to be working properly and does not blow the 15amp circuit. For what it's worth, the water pump switch functions fine too.

Thanks again for all your help!

Ed