Not Charging House batteries

bill jones · 01-01-2005, 12:34 PM

Before I go thru the whole routine making an appointment with my dealer, for god only knows when, does anyone know why my alt. is not charging my house batteries while driving? The invertor/charger is working correctly. Works fine while plugged in to exterior power but no charge on house batts. while on the road. I'm not sure it ever worked. We're usually plugged in. Is there another breaker I'm missing?

bill jones · 01-01-2005, 12:34 PM

Before I go thru the whole routine making an appointment with my dealer, for god only knows when, does anyone know why my alt. is not charging my house batteries while driving? The invertor/charger is working correctly. Works fine while plugged in to exterior power but no charge on house batts. while on the road. I'm not sure it ever worked. We're usually plugged in. Is there another breaker I'm missing?

Cruzer · 01-01-2005, 12:43 PM

When the key switch is turned on, it feeds a 12 volt signal to engage the charge solenoid. The charge solenoid connects the house batteries to the chassis batteries while driving so that the engine's alternator can charge both systems. If your alternator is working fine and charging the chassis batteries, but the house batteries are not receiving a charge, then the charge solenoid isn't doing it's job. Either the solenoid is bad or else there isn't any power coming to the solenoid's coil when the engine is running. Check for voltage presence when the key is on. If there is 12 volts there when the key is on and no voltage when the key is off, then the charge solenoid isn't working.

bill jones · 01-01-2005, 01:45 PM

Thanks Mark, I will try to find the charger solenoid, I see the Batt disconnect relay and the Aux start solenoid but not the charge solenoid. Did notice when I push the aux start sw. the batts parallel. Wiring diagrams from Winne are a nightmare. Remind me of some radar schems I had once. Again thanks.

zertrider · 01-01-2005, 03:36 PM

The charge solenoid is located behind the access panel under the hood, just to the left of center when facing the unit. Kind of a pain in the a$$ to change, but kind of a common problem. What you can try to do is repeatedly push the aux. boost button on the dash to try and break through the corrosion which typically builds up on the contacts. They are the same solenoid.

bill jones · 01-03-2005, 10:33 AM

After further investigation, I found that in theory, there should be +12v DC on the control terminal (wire LR) of the Aux start solenoid when the engine is running. This connects the house and chassis batteries together when to charge both batteries. The +12v control voltage is not there! Pressing the Aux start switch will engage the solenoid. Where am I loosing my +12v when the engine is running? Anyone? Bye the way, the reason I'm doing this is my closest dealer is 60 mi away and I have an appointment a week from Thursday. Gee, great support.

troth · 01-04-2005, 01:46 AM

bill j, this might sound weird but I recall there are some pushers (Journey & Horizon?) which do not charge their house batteries when driving down the highway. They only get charged from using the generator or plugging into a park pedestal. I don't know why they made some coaches this way, but yours might be like this and you do not have a problem because it simply doesn't have the capability...
Just my 2 cents.

Cruzer · 01-04-2005, 04:43 AM

Bill,

Your charge solenoid get's power from two sources. One is when you press the Aux Start switch, which you have verified is happening. The other is when you turn the key switch on. The Meridian uses a Freightliner chassis, similar to my Allegro Bus. My Bus feeds power from the key switch to a Freightliner relay and fuse panel that is located on the floor underneath the center console. You pull the drawers out and have access to it. I don't know where Winnebago locates this panel but the wiring harness is supplied by Freightliner so I'm sure that it's probably in a similar location. The key switch power feeds this box. From here it splits and goes all over the place. There are a number of fuses and relays there that feed "ignition" power to a number of places. If you pull the cover off there are labels inside the cover detailing what is what. Check for a bad fuse and also swap a few relays around to see if you can locate a bad one. This is probably where your open circuit will be found. Once that's fixed, you should have 12 volts at the charge solenoid when the key is on.

bill jones · 01-04-2005, 10:31 AM

The latest in the search for the elusive starter solenoid.
1. Called local RV dealer, York RV. They say the fuse and relay are on the front end by the breaker panel: Not there!
2. Called Winnebago cust. Serv. (RON) He says the solenoid is in the Battery compartment mounted on the back wall near the engine: Not there!
3. Called La Mesa RV (Carl) He said look in the compartment where the inverter is, on back wall. Found two fuse boxes, I now now where the fuses and relays for the computer and rear lights are: Solenoid not there! But, Carl is going out into the lot to look on some Meridians.

What learned so far:
1. Winnebago puts these solenoids where ever they feel is a nice location at the time.
2. The locations are not called out on the wiring insl. drawings.
3. As far as I can determine, the starting solenoid is not on Winnebago schematics.
4. I may admit temporary defeat and wait for my appointment a week from Thursday.

Sure is fun.

CaptBill · 01-04-2005, 01:48 PM

Bill, when you open the access door on the front of the motorhome, is there another access panel that is removable with 4 T-handle fasteners? (above the generator on the firewall).

If so, removing it exposes a number of fuses, circuit breakers, and little black relays. What do you see all the way to the left, down near the bottom of the distribution panel housing??? On my 2002, that is where the solenoid is. It has two heavy-gauge red wires and two smaller, (#14) on the terminals toward the front.

If your's is like this, the white wire is the ground and the yellow the +12 to activate the solenoid. Mine has voltage on it either when I press the battery parallel switch on the dash, or whenever the engine is running. I thought '04 Meridian had the same setup.

bill jones · 01-04-2005, 06:53 PM

Capt Bill, That's what I keep asking.. The small yellow wire (LR) only has 12 volts when I push and hold the Aux Start switch on the inst panel, nothing when engine is running. My question still is, how do 12 volts get on that wire when the engine is running. Schematically ( nice word) there is no splice on that wire run. It goes right from the switch to that solenoid. By the way, that solenoid is marked the aux start solenoid. The system would work if I spliced run only 12 volts on to the wire (LR) That is the only place I find both the coach and chassis heavy current cables run together. I wonder weather the system ever worked corectly?

Cruzer · 01-05-2005, 04:58 AM

The Charge Solenoid on my Bus has two wires connected to it - one from the auxiliary start switch and one from the key switch. Well, actually it's fed from one of th relays on the Freightliner breaker panel I mentioned earlier but it eventually goes to the key switch. I'm thinking it's one of those fuse or relays that's causing the problem.

CaptBill · 01-05-2005, 06:54 AM

Bill, I downloaded and checked the wiring diagrams for your 04 Meridian, and found that the 12v wire from the soleniod is only wired to the aux-start momentary switch. It is wire #LR. I know this doesn't help you, but at this point I am wondering if Winn has changed their mind about charging the house batteries in this way.

I would call the customer service # again, and talk with somebody who can verify how/if this is done on your coach.

bill jones · 01-05-2005, 01:18 PM

Found the problem!
There is supposed to be +12vdc on the other side of the aux start switch, this is run only (read as key on) and comes from the Aux start solenoid relay. Not in my case because there is no ground supplied to the aux start relay. The origin of that ground is buried. Easy fix..supplied new ground and all works as advertised.

This tells me several things:
1. Correct wiring diagram for my coach is labled wire asm 148433 Rev-D1 with MMDC wiring.
2. This aux start reley may have never worked on my coach
3. This is probably a good indication of Winnebago's documentation. (wire LLJ & LLH are not on the to from charts)
4. Jumping across wires LS & LR thru a switch will allow you to keep your COACH batteries charged while plugged in to shore power. Would work well if you plan to stay plugged in for long periods of time.
5. I'm nt nearly as smart as I think I am.

Thanks all for the help and support. It's Miller time for shure!

BucknJeff · 01-05-2005, 03:01 PM

Another thought...

The relay that WI uses for the aux-start I think may be supplied by intellitec. The manner in which WI wires this relay defeats its purpose to some degree.

Consider:

The "House" batteries are connected to the "Chassis" batteries whenever the ignition key is in the "ON" position.

Lets say that you have dry camped and run the house batteries down pretty low. You figure, no problem, they'll charge on route to the next place. It's a cold morning. You turn your ignition to the "ON" position to allow the glow plugs to pre-heat the intake. This draws considerable amperage. While you may not realize you are also connecting the large load of the "low" house batteries into this equation by means of the aux start solenoid, connected whenever the key is in the "ON" position.

Will you have sufficient power to start the engine, given all of the loads? What if the alternator should fail while underway? Wouldn't both battery banks be drained? I suppose the idiot light might come on, but if not, you might get yourself into a pinch if you inadvertantly drained both banks of batteries.

I have always thought this was a poor design. Intellitec makes a device called a B.I.R.D. short for Bi-directional Isolator Relay-Delay. This is esentially a logic circuit to control the house/chassis solenoid. They also make a more robust heavy-duty isolater solenoid they called the Big Boy.

WI "infers' that the BIRD device (or a similier one way device called the IRD, which is a smart delay control device with low voltage logic) is included on the Horizon, and actually did install it in the Ultimate Freedom line. When I questioned its absence on my Horizon, they replied that it was prone to failure, and that's why its not installed. I have spoken with the people at Intellitec several times, and they say otherwise.

The device monitors the voltage on both the house bank and the coach bank. Whenever either bank rises above a set voltage (I think its 13.3) for more than 12 seconds, it allows the solenoid to close. If either bank falls below 12.8 for more than 5 seconds, it disconnects the banks. This acomplishes several things. First, it allows the inverter/charger to keep the chassis batteries charged while plugged in. It also eliminates the "low start trap" I outlined above. Additionally, it can apply full current to the solenoid to get it to close, and then ramps down the voltage to about 4 volts to hold it closed without baking it to death. Pretty smart, Huh? It also prevents overloading the alternator or inverter/charger should either battery bank overload or over draw. Also, if you choose to make an over-ride for the WI system, and close the isolator while parked, what happens if you loose your inverter/charger output, or draw more than it can produce? Won't you draw the chassis batteries down, potentially without knowing? When the park pedestal breaker opens, or there is some other power failure, whould you know in time to avoid dead batteries in both banks?

I am going to replace my aux start solenoid with Intellitec's "Big Boy" Diesel solenoid, which is designed to work with the BIRD, and is rated for continous duty (only when connected to the BIRD controller).

After more than a few problems not unlike the one above, I'm done with WI's solution.

Have a look at the BIRD [URL=http://www.intellitec.com/pdfs/BATTERY_web/bird.htm]

bill jones · 01-05-2005, 03:59 PM

You know I have had a similar system in my last rig ( Rexhall Airbus) built by intllitec. While dry camping, when the house batt. would drop below a certain voltage, you could hear the solenoid drop out. There were times when it would go back and forth two or three times but it was a good design. Intellitec tech support was great. What WI should have done is attach a time deley relay to the aux start relay (about 90 sec) to delay the dreaded low start trap. Maybe they did only mine is a 7 month delay.

CaptBill · 01-05-2005, 04:18 PM

Hey Bill,

Glad you found the culprit and got it working. The idea of a 90 second time delay is good. I have 12 volt 0-120 second time delay relays available to me thru one of my vendors, so I might take that idea and run with it. Thanks.

The Intellic system is a better design, but the one Winnebago is using works, probably under all but the most severe conditions, as Buck n Jeff described, and it certainly cost less. That would be the more shareholder friendly design!

bill jones · 01-06-2005, 10:59 AM

CaptBill,
Would be great if the TDR would replace the aux start relay presently in there. Then you could come up with a relay to sense external 120vac present (not inverter output) and close the aux start solenoid, for chassis battery charging. This could go on for ever. Techies will always putter. Thanks for the help.

CaptBill · 01-06-2005, 04:35 PM

How right you are Bill. I ordered a B.I.R.D today from Intellitec, and will incorporate it into my charging system so that it will charge both battery banks when either one is receiving a charge. The price was very reasonable.

BTW, Intellitec told me that they have had NO reliability problems with this design, and that Winnebago is definitely still installing them in their top-line coaches.