12 volt charging system - seems Winnebago put a "annunciator"

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Don88203

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Jul 30, 2013
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Just to add, I bought a "new" 2006 Ellipse back in 2007. My "list" ended up at over 100 items, everything from the a/c non op (both dash & coach, dash air NO Freon and was missing a schrader valve AND control for the electrical condenser fan was disconnected behind the dash) cracks in the solid surface counters (replaced 3 times) cracks in the shower (at the top where it is screwed to the framing & running down 6 to 12 inches) and the little things like in-op gas furnace, water heater, water pump.... and the rig spent 10 of the first 12 months in the shop for service. The coach a/c issue I ended up fixing myself as well as the dash air (lucky I'm a contractor and EPA a/c licensed refrigeration tech) it turned out to be the freeze sensor on the evap coil was marginal in resistance and kept shutting down the system on a 3 minute cycle. (Why couldn't 3 different dealers fix this? AND freightliner charged me $100 to tell me that nothing was wrong with the a/c)

Ok, enough ranting about past problems, the one problem I have NEVER discovered a cause much less a fix to, is the 12 volt charging system. Seems Winnebago put a "annunciator" (which senses voltage) at the dash to control the charging of the house batteries. It turns on the charging circuit to the house batteries at 13.5 volts and shuts off charging at 13.0 volts. (OK, I understand this, its to keep the chassis batteries at full charge for starting and not to leave you stranded) there is a .5 volt drop between the batteries and the dash, THERE IS ANOTHER .5 VOLT DROP WHEN THE THROTTLE IS ENGAGED! Even in neutral if you bring the RPM's up to anything over 800-900 on the Cat C7, the voltage at the dash drops! The voltage at the batteries HAS to remain at over 14 volts for the system to charge. (and it doesn't) At night with the lights, in the summer, with the dash air going, maybe in the rain with the windshield wipers going..... I can always tell when it gets into its "cycle" mode (which it sometimes or should I say usually does even in the daytime) at night because the headlights are going bright / dim, bright / dim on about a 15 second cycle as the battery voltage goes 13.5 - 12.8, 3.5 - 12.8 I've had it at 2 Freightliner dealers, 3 Itasca Dealers and 2 Cat dealers, NADA on cause or fix. I must say, one Freightliner area supervisor had the maintenance department put in over 50 man hours (and they were in daily communication with Winnebago) to no avail. Usually I get the runaround (its a Winnebago problem, no its a freightliner problem, no, Cat supplied the alternator and then start over) This is another issue that freightliner charged me to say there's nothing wrong (first dealer 2 weeks after purchase)

Any Ideas????
 
Don88203 said:
Seems Winnebago put a "annunciator" (which senses voltage) at the dash to control the charging of the house batteries. It turns on the charging circuit to the house batteries at 13.5 volts and shuts off charging at 13.0 volts
Annunciator? Never heard of such a thing.  What you have is a battery mode solenoid that bridges the house and chassis battery banks together when a) the engine is running or b) when you operate the battery boost switch.  I changed out my battery mode solenoid for a smart version which does sense voltage of the chassis batteries and won't operate until the chassis batteries come up to a certain voltage.

The voltage drop you mention - you will not measure the same voltage everywhere in the 12V system due to wiring differences (length of the wiring run, etc.)
 
John Hilley said:
An annunciator is a panel or display that shows status and alarms of systems
I understand what an annuncator is, I've never heard of ""annunciator" (which senses voltage) at the dash to control the charging of the house batteries."
 
I thought it best to define annunciator for those that don't know and go off on an "annunciator voltage sensing tangent."
 
The annunciator on the dash simply displays the voltage available at it's input terminals.  It does not do any "sensing" for the purpose of controlling the charging of any batteries.  If your coach has any sort of smart relay or BIRD function, with threshold voltages to control the ON/OFF status of battery charging, it was definitely put there by Winnebago.  (The range of voltages that you quoted, 13.5V ON and 13V OFF, are not correct, so either the circuit is faulty or your understanding of it is faulty).

Your alternator should be putting out enough voltage (in the 14.2V range) to completely override the threshold voltages and keep the bridging solenoid picked.  The headlights should never have to depend on the battery mode solenoid or the coach batteries to remain bright.
 
What is the voltage at the alternator output, should be over 14v. What is voltage at chassis battery? I had a similar problem, similar symptoms, it was a huge part of why previos owner was selling. PO had to run gennie to drive it, had a new long block installed 2 years and 2000 mi before we bought it. Asked an aquaintance, where to start. His family business is "Yankee Auto Electric" in Hyannis, MA., highly recommended if you have troubles on Cape Cod. He suggested starting at the alternator output on the back of alternator. Should be 14-14 .7v, if you have the voltage, just follow that wire 'till you don't. Soooo,,,,, left the engine running, and manually traced the wire with my fingers. The movement of the wire, from me tugging on it, caused the alternator to take a load, wiggling caused the alternator to load and unload. Alternator whirring noise gets louder, the bigger the load the louder the whirring. Found a positive + buss bar less than a foot away from the alternator. Buss bar had 5 wires, 3 could be wiggled, including the alternator wire. He had the alternator replaced twice trying to fix it, once before new engine, once with new engine. Actually quite a few issues on my 20 year old rig were caused by the wiggley-jiggley nature of the life of a house on wheels. Quite often it's just something that is loose. Part swapping mekanix just throw parts, trouble shooting is becoming a lost art, not many people left to learn from. I'm bummin'.

Bill
 
Sounds to me like your chassis battery is fully charged but your house batteries are not.  When you turn the ignition on the solenoid that bridges the two batteries is engaging and the house battery is dragging down the available voltage.  I would fully charge your house batteries (or confirm they don't need replacing) and try your tests again.
 
Sloop said:
Sounds to me like your chassis battery is fully charged but your house batteries are not.  When you turn the ignition on the solenoid that bridges the two batteries is engaging and the house battery is dragging down the available voltage.  I would fully charge your house batteries (or confirm they don't need replacing) and try your tests again.

That makes some sense, but the alternator should still be able to keep up. It would be a very good test to try however.
 
driftless shifter said: " the wiggley-jiggley nature of the life of a house on wheels"

That's one of the most descriptive phrases I've heard in a long time. I hope there's no copyright on it. Thanks!

Ken
 
Thanks everyone:

annunciator is what "John", Winnebago tech support called it (first time I ever heard of something like that call an annunciator) . I was told it controlled the solenoid at the back of the coach in the shore power compartment, that then connects the house and chassis batteries in parallel for joint charging.  "John" also specified the voltage differential of 13.0 Volts for disengagement and 13.5 volts for engagement. This is exactly how it is working now.

I replaced the alternator with a 300 amp model (at my expense since I didn't trust Freightliner and Winnebago when they said nothing was wrong with it) (Cat did say there was an alternator problem) and had the techs make sure at the time the voltage from it was peaked at 14.6 to 14.7

Another "tidbit" is that I GET 14.3 to 14.6 at the batteries on the passenger side of the coach (as opposed to the front "under the dash" depending on what is drawing power at the time. BUT I also loose that 1/2 volt when the C7 Cat running at anything above an idle, even at the batteries themselves.

I've thought for some time that it's a "loose" ground but have never had / taken the time to trace all voltages from the back to the front. and yes driftless shifter I too run the genny almost 75% of the time the coach is in motion. Of course, most of our travels are in southern New Mexico, southern Arizona, southern California, south Texas.... so its not a GREAT issue since we usually want the A/C going anyway, even in Dec when crossing desert.

Also, (thanks Sloop) it doesn't seem to matter if the house batteries are fully charged, new or old (btw, I just put in the 5th set of coach batteries since new in May 2007). SOMETHING is drawing major amounts of power from the coach batteries & that's another issue altogether! (When this coach was wired, the engine block heat and water heater were run through the inverter and I haven't corrected that issue yet either)(why would ANYONE, EVER want to heat water or the engine with the batteries?) Still, with at minimum 250 - 300 amp hours of batteries, you'd think that we could go to bed watching sat TV and have enough juice to run the propane furnace when dry camping overnight. Just so I'm clear, we (I) set the TV to go off in 60 to 90 minutes and have the furnace set to gas and 66 degs. All coach lights are either LED or fluorescent and we run out of power to operate the furnace in about 5 to 7 hours. (so.... maybe 120 watts on the TV {12 amps x 1.5 hours, if anyone knows, please let me know, but I would guess no more than 6 amps for the king dome and parasitic loads from cell phone chargers and microwave = 18 amp draw for 1.5 hours} by that reasoning there should be at bare minimum another 250 - 270 amps to operate the furnace. ( I really don't like getting up between 3:30 and 5:00 AM to start the genny)

Guess the big issue (which hasn't been big enough to get me to crawl under the coach and starting tracing wires) is the voltage drop when running and the voltage drop back to front. If only one of these two were corrected it would charge like it is supposed to. (did I mention that Freightliner put in numerous hours in conjunction with Winnebago and couldn't find the problem?)

I'm at the point that I don't really care anymore what is or is not mis-wired, I am thinking of removing the automatic function of this solenoid and either making it go to on when the engine is running, or use a smart switch, or perhaps a stepping relay controlled by the momentary contact battery boost button. Have to find space for an indicator light at the drivers position and at the power control panel to show when the batteries are in parallel.
 
I asked my Winnebago contact to review this situation and here's the reaction:

To clear things up a bit, this is the only device, "Trik-L-Start" that we install on the Tour/Ellipse that toggles depending on voltages.  The intent of this component is to engage the Dual Battery Solenoid when plugged into shore power, this occurs if the chassis battery voltage is more than a half volt lower than the house batteries.  It was incorporated to keep chassis batteries up when on shore power.  What the owner seems to be describing is a BIRD module, Bi-directional-Isolator-Relay-Delay.  We did use that in our Ultimate line but not on the Tour and Ellipse.  I would begin my diagnosis by referring to the on-line diagrams, identify the location of the isolated studs and verify that the nuts are tight and the crimps are good on the positive and ground cables.

On a side note, not sure who John is, we have not had a John in the O.R. or Tech Service group for over 15 years.


I recommend you disconnect the Trik-L-Start and see what kind of results you get.
 

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Ok, now you've got ME wondering, I'll have to dig out my old cell phone from 5 years back and see who exactly, and what ext. I plug'd in for Winnebago tech support. Needless to say I'd given up hope that anyone from Winnebago, Freightliner or Cat could solve this many years ago.

REMEMBER....this was a first year build for the ellipse model, its more than possible that not all  is as its supposed to be on this coach.
Chassis batteries have never been an issue at any time, nor have the coach batteries when plugged into shore power.

John, please explain how the Trik-L-Start could effect the system when not on shore power or genny power?

In the meantime I'll dig out the schematics and trace the control wire from the relay solenoid forward and see what they say it should be hooked up to "annunciator/BIRD" module

BTW John, any thoughts on that 1/2 volt voltage drop when the engine is over 900 RPM?
 
Don88203 said:
REMEMBER....this was a first year build for the ellipse model, its more than possible that not all  is as its supposed to be on this coach.
Your electrical system has been basically the same for several model years.

John, please explain how the Trik-L-Start could effect the system when not on shore power or genny power?
There are reports of the Trik-L-Start causing problems, I have a Blue Sea intelligent solenoid and a Xantrex Echo~Charge and have never had a problem, so I have no personal experience with the Trik-L-Start.  I have had several solenoid failures before I switched to the Blue Sea solenoid.

In the meantime I'll dig out the schematics and trace the control wire from the relay solenoid forward and see what they say it should be hooked up to "annunciator/BIRD" module
You don't have a BIRD.


BTW John, any thoughts on that 1/2 volt voltage drop when the engine is over 900 RPM?
A 0.5V delta is no concern IMO.
 
Ok, far as I can go tonight, my vision is starting to blur from all the schematic sheets.

From observation, the aux start solenoid located in the  power cord compartment cycles on and off constantly when the main engine is running. This is a fact, not speculation.

Starting at the aux start solenoid (pg 36), LR appears to be the control voltage . Following "LR" it goes to a main wiring junction (pg 38) located in the left front compartment
page 16 has "LR" exiting to page 15 to a 12 pin socket/plug which then picks up again on page 22 where it connects/terminates to the battery boost switch on the dash.

At the boost switch, you have "LR", "EEE" which appears to be 12 volt positive (as shown on pg 17) and "LLJ"

Following "LLJ" through pages 21 and 16 it connects to another 12 pin connector on pin #10.

And that's where I quit tonight. Best I can see there must be some sort of control throwing 12 volts to "LLJ" causing the aux start solenoid to energize and cycle. Where to find the the termination of "LLJ" now that's the question.

maybe tomorrow.







 
In typical motorhome wiring, the aux start relay also serves as the house battery charge relay when the engine is running. It is cycled based on voltage state, i.e. the relay is closed if the house batteries are low enough to need charging and the chassis battery is high enough (alternator actively charging) that it can afford to share some power with the house. Fairly rapid cycling can occur in certain combinations of house and chassis battery status. For example, weak house batteries can quickly suck a lot of amps from the chassis side and cause a voltage drop to the point where the relay opens to protect the chassis battery from discharge. At idle, the engine alternator is not putting out a lot of amps, so its fairly easy to make the charge controller open the aux start/charge relay.
 
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