Grave Yard Dead Brand New Battery.

up4306 · 10-27-2015, 08:33 PM

Hello,
I am looking for input as to what I may have done wrong to end up in this situation.
Picked up the Axis last week and had it around the house here getting ready to go. Ran the engine, generator, etc.. I did not have it hooked up to 30 amp service prior to leaving home.
We arrived at the Maryland State Fair grounds last Thursday night and hooked into a 30 amp service pedestal. Set the rig up for a 2 night stay.
All worked very well with no complaints at all.
Sunday afternoon as I reloaded the rig I decided to start the engine and let the motor warm up only to find the battery grave yard dead.
Dead like, no dash indicator lights, no head lights, nothing.
I double checked the manual and went ahead with holding the emergency start switch for 30 seconds while turning the key. Still nothing.
Started the generator just to keep the coach bats up. Contacted the folks at Thor who walked me through the the emergency start again. Nothing happened.
He could offer no further assistance. Was surprised to have someone at Thor actually answer the phone. Thanks, Thor.
Went on to calling Good Sam and had a jump arrive in 30 minutes. Thanks, Sam!
However, he wasn't told it was a heavy duty jump that was needed and only had a plastic box in his hand that he said he had charged the night before?
Pressing on I held some duct work out of his way while he hooked to the hot terminal and to the frame. I went inside and started the rig right up with no hesitation at all.
I did notice the amp needle in dash come to the middle of the icon and stay there. Not high or low.
We departed and drove home and did not turn off the motor anywhere along the way. The amp needle stayed centered the whole time. No other issues were encountered.
I shut off the rig and the next morning it started right up after a chilly night.
Part of me thinks that a completely dead battery would have needed more than a hand held box of juice to start the motor. Why didn't the house batteries make a difference after holding the emergency start toggle? Not even a click of the starter. I did remove the GPS from the cig lighter outlet. Headlites were in the off position. Though the radio screen was lite the radio was not used.
The only thing I did add to the coach before leaving was a blue ray player plugged in over the sink.
With that I turn it over to you good folks. The thought of taking it in for service for an electrical issue is not up for consideration, yet.
My first blush is a battery terminal connection.
When it stops raining for more than a minute I will check that first.
Thank you for any input you may have with this issue.
I am new to all this but I must say it is odd the way part of the dash is hot with the key removed, part is not. Radio is hot in the dash when the house is on.
Radio is not hot with the engine running and house off. Hmmmmmmm.
Best to all and thanks, again!
David

DocMike · 10-27-2015, 09:45 PM

David,

Wowsers, a dead battery...dead with no smoking gun to help figure it out. In my run in with dead batteries (see thread Final Report Harris Batteries & WFCO...) I was referred to John, j.klocek@wfcoelectronics.com.

Email him with what you have going on, he is the senior tech. at WFCO and should be able to help send you diagnosis the problem and - hopefully - in the correct direction.

Doc

bevedfelker · 10-27-2015, 10:01 PM

Just to clarify -- this was a dead battery in the chassis for the Ford not the battery for the "house." And when you used the emergency start that should have jumped power from the house battery to the chassis - there was no response. Am I right?

And I think the radio is designed to be powered off the house batteries not the chassis battery -- so when you are using the radio when boondocking you are not draining the chassis battery.

up4306 · 10-27-2015, 10:10 PM

Quote:

Originally Posted by bevedfelker

Just to clarify -- this was a dead battery in the chassis for the Ford not the battery for the "house." And when you used the emergency start that should have jumped power from the house battery to the chassis - there was no response. Am I right?

And I think the radio is designed to be powered off the house batteries not the chassis battery -- so when you are using the radio when boondocking you are not draining the chassis battery.

Yes, the battery in the engine compartment for the motor.
The house batteries were completely charged but did not come to the aid when the toggle switch was held while trying to start. Not even a sound as is sometimes heard, clicking, etc.

groswald · 10-28-2015, 12:38 AM

I've found that the "emergency start" function will not start the engine if the chassis battery is truly dead. It will turn the motor over, the motor will start, the emergency start relay will kick off instantly, and the motor will die because the chassis battery is too dead to keep it running.

It will work if the chassis battery is too low to turn the engine over, but has some juice left in it.

It's not much help in an emergency... The coach batteries need to be left in the circuit long enough for the alternator to come up to speed and put a couple of electrons into the chassis battery.

I wonder if this is unique to the Axis or Thor.

Regards,

Randy

sikoriko · 10-28-2015, 06:33 PM

Did anybody run a load test on the battery? or check for a lose cable? I killed my battery by keeping the key in the ON postition, while tinting my front windows, yes forgot to turn the key off. So might as well try the emergancy start switch, yeup it worked. But I still needed to charge the chassis battery the a 12v charger.

**EA37TS** · 10-28-2015, 06:50 PM

I guess that brings up a question.

Is there a way to test the emergency start functionality without having a dead battery?

Chance · 10-28-2015, 07:24 PM

Quote:

Originally Posted by dstankov

I guess that brings up a question.

Is there a way to test the emergency start functionality without having a dead battery?

One way to replicate a complete battery failure (the kind that acts like an open circuit inside battery) is to disconnect the chassis battery. If engine starts solely off house batteries that would be a severe test of the switch and or cable sizing.

**EA37TS** · 10-28-2015, 07:37 PM

Not sure that disconnecting the battery would work because the starting circuitry may get its power from the chassis battery and if disconnected the starter may not engage.

Chance · 10-28-2015, 09:50 PM

Quote:

Originally Posted by dstankov

Not sure that disconnecting the battery would work because the starting circuitry may get its power from the chassis battery and if disconnected the starter may not engage.

If it's wired that way, it wouldn't be worth much to me. Why would you have a backup that required the primary source to be working?

JamieGeek · 10-28-2015, 10:34 PM

You might want to peruse this thread:
http://www.thorforums.com/forums/f8/...-box-1203.html
In it I posted some documentation for the circuit board in the drivers front outside storage box. The documentation includes the circuit diagram.

This circuit is what controls the charging of both batteries and the emergency switch.

**EA37TS** · 10-29-2015, 01:51 AM

Quote:

Originally Posted by Chance

If it's wired that way, it wouldn't be worth much to me. Why would you have a backup that required the primary source to be working?

The backup works if the battery is dead, not if it is missing which is what would be simulated by disconnecting the coach battery.

samven · 10-30-2015, 12:42 AM

Please, please do not disconnect your chassis battery and start your engine with the emergency switch. If you are unlucky enough for it to work as soon as the relay drops out you will destroy your voltage regulator. Without the battery to act as a giant capacitor the alternator will surge and poof goes the regulator.

To the OPs question, I think you are going to find a bad connection. Almost nothing draws from the chassis battery and if it was so dead that it would not light the dome or dash lights the portable starter battery would have been sucked down trying to charge the primary. I had to jump my wifes battery when she left the headlights on all day at work. I had to connect the jumper cables and run my engine at 2500 rpm for a few min before hers would crank and start but she still got a dim dome light before the jump.

groswald · 10-30-2015, 01:04 AM

Samven,

Good advice on not starting with no battery.

Unfortunately, the parasitic load on an Axis chassis battery is about 10 times what one would expect it to be. I measured it, with an inline ammeter, a few months ago. The numbers are posted in another thread around here somewhere.

We haven't figured out what causes it, but several of us have gone so far as to install a disconnect knife-switch on the negative chassis battery post. Problem solved.

Regards,

Randy

samven · 10-30-2015, 02:15 AM

groswald,

I did not know that about the parasitic load. Do you know if shore power or generator charges the chassis battery. I suspect not if it is like mine. The load must be something that Thor has added, I can not imagine ford would allow this. I would have my meter hooked up and start pulling fuses till I found it. If not that I would get one of those windshield solar chargers to keep it topped off. I have been thinking about one of the disconnects just to help theft proof the RV.

Chance · 10-30-2015, 02:25 AM

Quote:

Originally Posted by dstankov

The backup works if the battery is dead, not if it is missing which is what would be simulated by disconnecting the coach battery.

An "open circuit failure" in the battery is the same thing. Current won't go in or out at all. It's happened to me a couple of times. In an instant the battery can go from being fine to not being able to power the dome light in car.

When it happens it's hard to jump start because the damaged battery can't help start the engine. I got my old Mustang started by pushing it and drove it straight to shop for new battery. In my case it did not damage the regulator -- granted it was old technology by comparison.

**EA37TS** · 10-30-2015, 03:24 AM

Quote:

Originally Posted by samven

groswald,

I did not know that about the parasitic load. Do you know if shore power or generator charges the chassis battery. I suspect not if it is like mine. The load must be something that Thor has added, I can not imagine ford would allow this. I would have my meter hooked up and start pulling fuses till I found it. If not that I would get one of those windshield solar chargers to keep it topped off. I have been thinking about one of the disconnects just to help theft proof the RV.

The motorhomes have an isolator that does not allow the chassis battery to be charged by the generator or shore power. This is to prevent over charging the chassis battery.

samven · 10-30-2015, 03:55 AM

I have to start carrying a small battery charger and set of jumper cables with me. I would hate to have a generator and 3 batteries and still need to call for roadside to jump the engine.

JamieGeek · 10-30-2015, 11:44 AM

Interesting, according to the circuit diagram of the panel in the drivers front storage the interconnect relay (the emergency start switch) is powered by both batteries. Thus disconnecting either one should still work.
(You can find the circuit diagram in this thread: http://www.thorforums.com/forums/f8/...-box-1203.html )
Here is an image of it:

Near the top left is a box labelled "Interconnect Relay Driver" follow the PWR lead from its bottom right to the right and you'll find the two diodes that keep it powered as long as one of the batteries has a charge (and the ignition is on--note that the chassis battery power source is "Chassis Ignition Relay").

Which means: If your coach battery is dead, turning the ignition on(and/or engine running) and holding the emergency start switch down for any length of time should allow the coach battery to charge up a bit.

Likewise if the chassis battery is dead holding the switch down should allow the chassis battery to charge up (especially if the genny is running).

Thus my recommendation would be: Depending on which battery is depleted either start the engine or the genny, hold the emergency start switch down for a while; then attempt to start the other engine.

Of course this is an old diagram (1/27/2006) the circuit has changed (the image above is for Rev B and mine looks like Rev M)--but it is the same board (the board in my Axis has "RV Custom Products" and FW221 clearly marked on it--there is a pic in the linked thread).

**EA37TS** · 10-30-2015, 01:10 PM

Jamie,

I could be wrong but those are one way diodes and the way I read the diagram is power from the coach battery can flow to the chassis battery (direction of the arrow on the diode) but the diode on the line going from the interconnect relay to the coach battery prevents power from going from the chassis battery to the coach battery (flowing in the opposite direction of the arrow).

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