Chassis battery dead

Picked up our new 2552 on May 23.  Drove back to Pa about 600 miles.  We took the RV out for a couple of short drives since we came home.  We have not started up the engine in probably two to three weeks.  We have been going in and out during this time with the step opening and closing each time.  Today we tried to get in and the step did not work.  We then realized that the chassis battery is dead.  The trickle switch is not helping so we know we need to use our jumper cables to start the RV up.  My question is could the battery have gone dead from using the step over the last two to three weeks each time we went in to the RV?   Any insight is appreciated.
thanks, John D

Seems unlikely.  Mine went dead but that was over more like 2 months not 2 weeks.  One thing I would check is what if anything is still on in the truck cab.  Radio?  GPS?  Phone charger? Cab lights?

I'm not certain how the trickle charge button is supposed to work.  I tried it when my battery went dead and it just blew a fuse in the trickle circuit.  Had to use the jumper cables.  I asked at the factory and was told it is 'trickle' not to be used to actually start the truck but that is contrary to what I was told when buying.  They also said it only works with the ignition key on.  I asked if I could just leave the trickle switch on because my house batteries are being charged by the solar panels.   But they said it would only work with the key on and that really defeats the trickle charge from the house batteries idea.

Some folks use this product: http://www.lslproducts.net/TLSPage.html that keeps the truck battery charged from the house batteries.  This might be what I end up with since I have no worries about the house batteries going because of the solar panels.

Thanks for the info.  One other thing I did not mention.  I had shore power on during this time and the house batteries were left on.  Could that have drained the chassis battery by leaving the coach batteries on?

thanks,

Nope.  The chassis battery is isolated from the house by design.  You can drain the house batteries with no worries that you will not be able to start the truck.  The interconnect switch is supposed to let you charge the truck battery from the house batteries in an emergency.  That assumes everything is working correctly.

I just carry a set of 25' jumper cables which seems to work better.

The only other time I heard of something similar someone turned off the 12 V switch on the panel by the door.  I have the 50 amp plugged into a special line Jim installed at the shop. then he put a trickle charger on the chassis battery... So far it seems to work. and though we have heard of some hiccups we seem to have things running. I had counted on Jim and have been lazy and now I have to open my eyes and keep my eyes open so I understand what's happening. these little hiccups are big headaches.. Hope you get the real answer to how things are connected and supposed to work... good luck P

I would first check that the truck battery leads are tight, maybe even do a test on the truck battery, there is a chance you got a bad one. You might have had just enough juice to get it home.
Doug

I’ve used the button to charge the chassis battery. You have to hold it for several minutes before attempting to start the engine. It works but that doesn’t solve your issue with why the chassis battery was dead. I agree with others, check those battery connections, they don’t have to be very loose to cause a problem. This along with checking for a doom light etc that may have been left on.

Here is what I do. Works great.
1. Ignition does not have to be on.
2. I replaced the toggle switch with a on-off switch that is identical, fits in same opening and the two leads unplug and plug in without difficulty. Advanced Auto parts sold it, but I'm sure you could find anywhere.
3. I have solar panels that continuously charge my house batteries.
4. I leave the switch on when in storage and my chassis battery never discharges or boils. There are a lot of parasitic loads that will discharge that battery.

If you think PC made wiring changes, put a digital voltmeter on chassis battery, leave ignition off and hold that momentary switch in, the voltage will start going up.
Actually, on mine, there is a safety relay that opens when you turn on the ignition switch and the battery will not be able to be charged when holding the switch in, and you can't pull power from house batteries.

The battery crossover switch according to earl. To use the crossover switch turn the key To Accessory or on.  Press the crossover switch momentariy. You will hear the relay close.  wait 20 or 30 minutes. turn the ignition key off. This will open the relay. Use the key switch to start the engine. There is no need to hold the crossoverswitch.

The battery crossover switch according to earl. To use the crossover switch turn the key To Accessory or on.  Press the crossover switch momentariy. You will hear the relay close.  wait 20 or 30 minutes. turn the ignition key off. This will open the relay. Use the key switch to start the engine. There is no need to hold the crossoverswitch.

I wonder what year they changed this. My 2012 does not work like that. Sounds good.

The battery crossover switch according to earl. To use the crossover switch turn the key To Accessory or on.  Press the crossover switch momentariy. You will hear the relay close.  wait 20 or 30 minutes. turn the ignition key off. This will open the relay. Use the key switch to start the engine. There is no need to hold the crossoverswitch.

I was just going to post that.  Not sure when the change was made but on my 2017 there is a relay activated by the momentary switch that holds the circuit closed.  But the key has to be on.  And trying to start the truck with that circuit closed blows a fuse under the hold where the relay is at.  Thus the instruction to turn off the key before trying to start the engine, which opens the cross over circuit.

I asked them at the factory about leaving the cross over on so the solar panels would charge the chassis.  I was told the key has to be on for that to work, so not sure that is a good answer on my model.

Had a similar issue earlier this year. After a quick call to PC I determined the rotary domelight switch was in the on position and even though the cab lights were not lit it drew down the battery. I shut it off,trickle charged the battery and it started right up. No issues since..hope this helps.

Dave, there must be changes over the years. Mine you have to hold it for several minutes. Maybe mine has a hold it gremlin

I checked the battery and the leads are on tight.  I did jump the battery and was able to start the engine yesterday.  Took the RV for an hour drive today.  Started up this morning with no issues.  I did turn the dome light switches off.  I will continue to check to see if the battery holds its charge.  I will update all if and when I can definitely identify the problem we had.  Thanks for all the input and insight.

hello, I have had the Chassis battery go dead just letting it set for a month, Now I put a float charger on the chassis battery when ever I leave it parked for more then 4 days with out starting, I did put in a relay system for my Ham Radio, so that when I plug into shore power it turns on my 13.8 power supply to the radios and also switches power to the chassis battery. When I disconnect from the shore power the relay go over the battery only. Ford has a lot of power being used just setting. This also happen on all my vehicles, so when I leave on a trip I put the float charger on the car at home. Hope this will help

Jim