Engine Battery Drain on F53

John Locke · 11-28-2019, 10:46 PM

Many of us have the Ford V10 on the F53 chassis, like my Vista 32YE. One of the issues I haven't been able to solve is the engine battery going dead after about 3 weeks of sitting. Leaving the coach plugged in will charge the house batteries, but not the starter battery. Something is draining the battery slowly. It acts like a small light is draining the battery, but I've looked everywhere. My nephew has an RV on the same F53 chassis (not Winnebago) and he has the same issue. Without totally disconnecting the battery it will continued to die over about 3wks.

Does anyone else have this problem? Has anyone been able to pinpoint exactly where the power is going? If I can't figure this out I'll need to put a physical switch on the battery to prevent this drain during storage.

My last RV had a battery isolator switch on the engine battery, as well as a separate isolator switch on the house battery, but my 32YE doesn't have an disconnect switch on the engine battery, only the house battery.

Any tips on this would be appreciated. I'm tired of looking for the culprit, thx.

rk911 · 11-28-2019, 11:39 PM

you could add a https://www.lslproducts.net/TLSPage.html which will keep the starting battery charged while you’re plugged in to shore power.

when you’re not plugged in? about the only way to ensure there is no drain...zero drain...us to pull the neg. cable from the battery (PITA) or install or have install a battery disconnect switch.

John Locke · 11-29-2019, 12:12 AM

Quote:

Originally Posted by rk911

..... about the only way to ensure there is no drain...zero drain...us to pull the neg. cable from the battery (PITA) or install or have install a battery disconnect switch.

Yeah, that's my last resort. I'm hoping some cleaver person here has located the accessory that's draining the battery, that's my preference. I like to FIX the problem instead of putting a band-aid on it.

My Fleetwood RV had a disconnect switch on the engine battery, but even if I left the battery engaged, the engine battery still didn't drain dead in 3-4wks. It would last for months. Something is wrong with the RV design IMO. If nobody in this forum has figured it out I'll have to call Winnebago and bother them about this issue.

I wonder how dealers deal with this. They have RV's sitting for months. If they have to charge them weekly that would be a PITA.

be happy · 11-29-2019, 02:45 AM

Could it be the in dash radio? I know on my 07 Meridian I have a switch that I can select where the radio gets its power from.

thompwil · 11-29-2019, 05:07 AM

Do you have a repeater for your TPMS wired in? Trying to think of what it could possibly be. Our 2018 32YE does not have that problem.

rk911 · 11-29-2019, 08:46 AM

you need a way to, in real-time, measure the current load in amps. this might help you do that:

https://www.hagerty.com/articles-vid...suring-current

then unplug from shore power and turn off the inverter (if you have one) and the converter/charger. then trip all of the 12v circuit breakers or pull the fuses. don't neglect the automotive side. in theory you shouldn't have any 12v draw. re-engage the circuits one at a time until you find the one causung a draw with that circuit 'off'.

have you load tested your battery to be sure that it's retaining a charge? you might have a weak or bad cell(s).

just the other day my Jeep wouldn't crank after sitting fir about a week. i jump started it and had my buddy at the service shop do a proper load test. he found the battery was ok but the 16-yr old alternator was not defective. just a thought.

John Locke · 11-29-2019, 09:24 AM

Quote:

Originally Posted by thompwil

Do you have a repeater for your TPMS wired in? Trying to think of what it could possibly be. Our 2018 32YE does not have that problem.

This is a really good question. I think I connected the TPMS repeater to an ACC line, but I'll double check this weekend.

The radio dash switch is off, that was one of the first things I checked.

I do have a clamp on current checker, but was thinking the current was too little to detect. I'll try that this weekend. I also have an inline current meter, I'm sure that would work if the clamp on doesn't. That's a good approach, to remove fuses, however there are lots of fuses.

I'm glad to hear others don't have this issue on their 32YE, that's encouraging. Maybe it's simply a bad battery, as mentioned.

rk911 · 11-29-2019, 10:13 AM

john, if you don't have one pick up a hydrometer at an auto parts or home store. quick, inexpensive way to check the state of charge in the battery's cells. be sure to first charge the battery overnight, then remove the cables, let the battery rest for 15-20 min and then check the cells. not a substitute for a proper load test but it should give you an indication if the battery needs to be replaced.

John Locke · 11-30-2019, 07:53 PM

So today I tried to measure current flow of the engine battery with no luck. My meter that I thought would measure current inline up to 10A didn't work. I tested my house battery where I know there is 1.5A current flowing when my inverter is on. It detected no current. My clamp on meter worked on my house batteries, detecting 1.5A, but wouldn't detect any current on the engine starter battery, presumably because the current draw is quite low, likely around .1amp. I checked my TPMS and it's connected to an ACC line, normally used for windshield wipers, but for some reason Winnebago doesn't use it for their wipers. The wire was labeled wipers, but not connected. But it only provides power with ignition turned on.

I have a good portable load tester that's good for a 10 second high load test. The engine battery passed with flying colors.

I need to buy an inline current meter that works, then proceed with further testing.

I might buy a hydrometer too since I've always wanted one. I hope to get this done tomorrow.

SLOweather · 11-30-2019, 10:19 PM

Is your meter fuse blown?

John Locke · 11-30-2019, 10:29 PM

Quote:

Originally Posted by SLOweather

Is your meter fuse blown?

The voltmeter works, but the ammeter setting of the meter doesn't. I have never used the ammeter before, I've just always known it's suppose to measure current when inline to the circuit. If the fuse was blown I would think the whole meter would not work at all. However I'll investigate that notion to see what I can find. Thanks.

SLOweather · 11-30-2019, 10:38 PM

Nope. Most meters have a fuse just for current measuring. If it's a good meter with 2 amp ranges, there could be 2 fuses, as in my Flukes. If you have access to a second meter with ohms or continuity, check the first meter's amp settings. There should be little or no resistance.

SLOweather · 11-30-2019, 10:41 PM

P.S. It's really easy to blow a meter fuse by having it set to amps and trying to measure volts. I keep several spare fuses handy.

John Locke · 12-01-2019, 12:28 AM

Quote:

Originally Posted by SLOweather

Nope. Most meters have a fuse just for current measuring. If it's a good meter with 2 amp ranges, there could be 2 fuses, as in my Flukes. If you have access to a second meter with ohms or continuity, check the first meter's amp settings. There should be little or no resistance.

OK, good to know. My meter has a single setting for 10A capability to read amps. I'll check out the fuse tomorrow, it's easy to access.

powercat_ras · 12-01-2019, 07:59 AM

Quote:

Originally Posted by John Locke

...engine battery going dead after about 3 weeks of sitting. Leaving the coach plugged in will charge the house batteries, but not the starter battery.

At least on the 2015 chassis Vista 27N, Winnebago uses the Precision Circuits Battery Isolation Manager (BIM), and it is bi-directional. It will connect the chassis battery to the coach battery intermittently to keep the chassis battery topped up, IF the coach battery has a charging voltage present (at least 13 volts) and IF the chassis ignition switch is OFF.

Your operator's manual may say if this feature is still on current Vistas. If you don't have two disconnect switches side by side, one labeled Chassis and one labeled Coach then you may not.

On my Vista, if you operate the disconnect switch labeled Chassis the coach can sit and not run down the chassis battery for months on end.

Good luck.

tderonne · 12-01-2019, 12:04 PM

2018 doesn't have a BIM....

SLOweather · 12-01-2019, 12:41 PM

I should say, John, that our 2014 Sunstar exhibits the same behavior, engine battery going dead after a while, even plugged in. Before I installed the Battle Borns, I just jumpered the chassis battery to the house batteries. Now, I use a small float charger to keep it topped up. The smaller one from HF was too small, but my older Diehard is juuust right,

I did exchange a few emails with Winnebago about the isolator or BIM operation and the new batteries, but never resolved it. Whatever I have either doesn't work, or I don't understand it. Given the hack job of some electrical work done by the PO, he or his minions may have dorked it up.

John Locke · 12-01-2019, 02:12 PM

Quote:

Originally Posted by SLOweather

Is your meter fuse blown?

The meter has two fuses, .2A and 10A. The .2A is blown, so that must be my problem. The challenge now is to find one of those tiny fuses. Shouldn't be a problem for Amazon.

John Locke · 12-02-2019, 07:40 PM

I got the fuse replaced in the meter and it works now to read amps.

With all house and dash accessories off that I can find, the engine battery draws .3A. This sounds about right since it takes 3wks to kill the battery to a point where the engine won't start.

With the entry door open it pulls .6A, due to the light at the steps, which is apparently always on when the door is open, there's no way to turn that off.

It's interesting the steps are connected to the engine battery instead of the house battery. Maybe that's safer so the steps will always roll out when getting out of the RV after driving. That's likely when it's most dangerous if the steps didn't roll out. Imagine the steps not rolling out and you assumed they were, while carrying something that prevented visibility of the steps as you stepped out of the RV.

So now I have to start pulling fuses to find out where that .3A is going. I'll need my son to help monitor the meter while I'm pulling fuses. I'll schedule that for this weekend.

John Locke · 12-02-2019, 07:50 PM

Quote:

Originally Posted by powercat_ras

At least on the 2015 chassis Vista 27N, Winnebago uses the Precision Circuits Battery Isolation Manager (BIM), and it is bi-directional. It will connect the chassis battery to the coach battery intermittently to keep the chassis battery topped up, IF the coach battery has a charging voltage present (at least 13 volts) and IF the chassis ignition switch is OFF.

Your operator's manual may say if this feature is still on current Vistas. If you don't have two disconnect switches side by side, one labeled Chassis and one labeled Coach then you may not.

On my Vista, if you operate the disconnect switch labeled Chassis the coach can sit and not run down the chassis battery for months on end.

Good luck.

I was disappointed my 2018 Vista doesn't have a BIM switch. My 1999 Fleetwood had one. If I can't find the source of this power drain, I may have to install my own BIM.