Battery Help

Bogie · 06-04-2018, 03:44 AM

Went dry camping for a couple days and found a problem. My engine is not charging coach batteries. Just got back and haven't had time to start troubleshooting yet, but any good places to start?

2014 Thor Four Winds on E350

Thanks... A fun day after work tomorrow ahead of me. Also, whose great idea was it to run the dash radio on the coach battery? Real useful when that goes out.

By the time I noticed the battery was too low, it was too low to start generator. Had to cut trip short and drive an extra 4 hours home. Wife not happy lol

**16ACE27** · 06-04-2018, 10:52 AM

Could have used your emergency start switch to start the generator.

Bogie · 06-04-2018, 01:55 PM

What!? I thought it only started the engine from the coach battery? It goes the other way too?

I will have to try that before I start doing maintenance lol.

Bogie · 06-04-2018, 01:56 PM

So my three possibilities I see so far:

Bad fuse somewhere (?)
Bad solenoid (not sure where this is yet)
Bad battery

Bogie · 06-04-2018, 04:04 PM

Test results:

Engine Off:
House Battery: 11.7 v

Engine On:
Chassis Battery: 14.4 v+
House Battery: 11.7 v

When I put it in to USE mode from STORAGE
House Battery went down to 9.9v and was slowly going back up.

Engine Off / Plugged into Shore Power:
House Battery went to 13.34v

When I depress the emergency start switch I can hear the trombetta solenoid click, but I am can't hear it click when I switch the key to run, and there is too much other noise to hear if it is clicking when I turn the engine on.

I would guess though that if the engine were charging the battery that I should see the same ~13.3v number?

Travelin' Texans · 06-04-2018, 04:15 PM

Your house battery WILL NOT charge from shore power or generator if the battery switch is in "store". Once in "use", plugged into shore power & then checking the battery voltage it should always read 13+ volts as it not reading the battery but the converter charge going into it. Check battery voltage before plugging in & switch in "use", you'll probably find bad batteries or at least very low.

steve76 · 06-04-2018, 04:22 PM

My C class frame engine charges my batteries 14.4 V. Emergency start switch only works one way, to give power to the frame engine battery to start V10 engine, so if my coach batteries are dead, can't use the emergency start switch to start generator. That's how mines wired to work.

I carry compact jumper unit from Harbor Freight, just in case needed to put power into coach batteries should they not have enough Umph to start generator. Haven' needed to use it yet and hope don't have to.

Bogie · 06-04-2018, 04:40 PM

Yeah. I am starting to think I have a bad solenoid somewhere. While in use mode when I was driving the smoke alarm and other alarm started beeping and I lost my entertainment center. With engine on and use set it did not go up to 13+ v

steve76 · 06-04-2018, 04:55 PM

Bogie: Was you're dash radio on all the time you were camping and discharged coach batteries?

Bogie · 06-04-2018, 05:04 PM

Quote:

Originally Posted by steve76

Bogie: Was you're dash radio on all the time you were camping and discharged coach batteries?

We were dry camping for two days. I had run the generator for about 45 minutes one day. The dash radio seems to be wired to only the house battery and it doesn't have a way to turn "off" completely, but I can shut the screen down. It still drains power for sure.

I would expect though (could be wrong) with the RV driving for about 3 hours in "use" mode it would have charged the battery back up a bit? Instead it seemed to continue draining as the alarms and dash radio started flashing on and off so I had to switch over to storage mode.

This morning when I put the multimeter on the battery it showed 11.6v (no charge). When I turned the engine on and put it in use mode it dropped down to 9.9v so it seems that the engine is not charging the battery. I'll do some more tests when it is lunch time and I can run down to the RV again with a notepad.

Once I plugged it into shore power, the house battery jumped to 13.4v

steve76 · 06-04-2018, 06:06 PM

Yep, something went out on charging from running the rig engine. I just ran mine to pull out of garage, checked coach batteries and charging at 14.4. Shut off rig engine and started generator and checked batts running off genny and charging at 13.58V. I hardly ever use shore power to charge batts. I use a small trickle charger about once a month. After disconnecting trickle charger, measuring batts Voltage after 24 hr. rest, measured voltage is 12.85V. After 30 days drains down to 12.63. Clean connections etc. but there is still a trickle loss over 30 days. Guess maybe O.K. as still holding slightly above 12.6 which I read for 12 volt is 100%. Hope you get yours worked out O.K. I understand your dilemma, real PITA stuff to contend with.

Bogie · 06-04-2018, 06:10 PM

More numbers (fun with multimeter lol)
HB = House battery / CB = Chassis Battery

Generator On or Shore Power HB(13.4v)

Unplugged in Use mode HB(12.7v) at this point it had been charging only about 2 hours, but it was enough to start up the generator.

Engine Running for 5 min
CB = 14.4v
HB = 12.56v

Engine Running with lights and AC on for another 5 mins (10 total)
CB = 14.3v
HB = 12.52v

Since it should not be draining down with the engine on, is there a fuse I need to check? I can only find one solenoid which is under the coolant overflow (trombetta).

---
I suppose if I am only driving for 6 or 8 hours and always going to be on shore power, it doesn't matter. This time I was trying to keep generator usage to a minimum since I was dry camping near a lot of tent campers and did not want to annoy them.

I think after 6 hours of driving my battery was showing at 3/4 full before I plugged in but since at that point I did not suspect a problem I wasn't really paying attention. Usually while driving the only thing on is the reefer on LP and the dash radio, plus the various alarms.

Bob Denman · 06-04-2018, 06:13 PM

I keep one of these handy:

Rugged Geek 1000A Compact Jump Starter and Portable power Supply. Lamonster Approved

Bogie · 06-04-2018, 06:43 PM

Quote:

Originally Posted by Bob Denman

I keep one of these handy:

Rugged Geek 1000A Compact Jump Starter and Portable power Supply. Lamonster Approved

Definitely useful if it will jump the generator off the house battery.

Mostly I am worried as the next trip is planned for two weeks and I don't want to have to stop and turn the generator on every three hours or so to recharge the battery so I can use my radio. I get why they rigged it that way, but I think I need to rewire it on a switch so I can cut it over to the chassis battery if I ever need to.

Bob Denman · 06-04-2018, 06:57 PM

It'll start the V-10...

Travelin' Texans · 06-04-2018, 07:26 PM

With your engine running you're measuring your alternator output on the CB, whether that output is getting to the HB I don't know how/if Thor wired that way.
When connected to shore power or generator you're measuring the converter output to the HB. It sounds to me your HB are toast & won't hold a charge.
With a set of jumper cables you should able to start the genny from your CB.

lazinskm · 06-04-2018, 07:34 PM

Slightly off topic but not much- Just a reminder that the radio works off the house batteries, but not the 12v outlets in the dash- they are off the chassis battery. On the upside I know verified my emergency start switch works.

Bob Denman · 06-04-2018, 07:38 PM

https://www.youtube.com/watch?v=qs-ANd7ZncQ

Bogie · 06-04-2018, 07:48 PM

True. But in theory, even if the house battery is dead, I believe (according to the manual) it should have recharged from the alternator while driving. Since that is not happening, even if the battery is bad, it is taking a charge from other sources so it isn't dead yet. I was able to fire the generator after two hours of charging from shore power.

According to multimeter no power is getting to the house battery to charge it while the engine is running, otherwise I believe I should see 13.4v just as with the other sources that are charging (gen/shore). I could be wrong though, since I have not done much of this type of work before and only God knows how these RV's are wired up. It would be nice if the manual had some wiring diagrams.

When I pull the battery to check the water level, I'll disconnect the chassis battery and remove the coolant overflow as well so I can go through all the connections that I can see, clean them, and tighten them back down.

Before I pull the solenoid though, I was hoping to find the location of the fuse for the charging system, and whether that solenoid was the only one, or if there is another one. I suppose while the engine is running I could have someone hold the battery boost button down and see if I see any change on the multimeter.

Bogie · 06-04-2018, 07:49 PM

Quote:

Originally Posted by lazinskm

Slightly off topic but not much- Just a reminder that the radio works off the house batteries, but not the 12v outlets in the dash- they are off the chassis battery. On the upside I know verified my emergency start switch works.

Oh man! This is great news. I wasn't even using my phone because I was afraid it would run out of charge. Now I will bring a cigarette lighter adapter.

You may also like: