-
Chassis Battery “BAT” lite on
After driving Thursday night about 2 hours the Vanner Monitor turned the “BAT” light on the on. We had about 10 minutes to get to the track so we continued and parked. Next morning, fired the bus up and after about 15 seconds of run time the light came back on. Communicated the problem to Jeff Rowe and he said to check the voltages at the VAnner Equalizer.
Engine off: 25.0/12.3
Engine on: 27.5/12.5
Apparently the 12volt side should half the 24volt side (or 13.8).
What experiences have the PC members had with this? Voltage regular maybe? Vanner Equalizer? The Vanner Monitor was new in April.
We’re two hours from home. Should I risk that trip? If not, I need to fire the coach up and move it outside the main gate tonight. Is that OK? Or should I beg to stay put? We head to Tennessee for the Maintainance Seminar at Jeff’s on Thursday. I hope I don’t need to take the coach down there on a lowboy.
We’re at Blackhawk Farms Raceway between Beloit (WI) and Rockford (IL). Any good resources in the area? We are without a street vehicle.
-
21 Replies
-
Dick,
Don’t over think this. At the monitor are the voltages you want to measure. Measure all on the input side.
You should have a ground, 12V and 24V. Start the engine. Measure the 24 volt input. It should be around 27.5. The 12 volt reading should be half of what you read at the 24 volt side.
If the above values are what I stated you have no problem, except the monitor has gone bad.
If the 24 volt reading with the engine running is outside of the 27.5 volt reading by more than a volt or so the problem is with the alternator or voltage regulator. If the 12 volt reading is not half of the 24 volt side reading within 1/2 volt you may have an issue with the equalizer.
The monitor will light a light on the dash if the voltage reaches 31 volts, or is as low as 24 volts, or if the 12 volt reading is more than a volt from being 1/2 of the 24 volt reading. The Vanner monitors are an excellent device when they work because that is how you get the warning lights. But they do not have a good history of reliability.
-
I had the same symptoms on a run to an Indy car race in Iowa probably six years ago. Made it home no problem. Any 12 or 24 volt load that you are running is at risk because as voltage goes down, amps go up = heat = fried loads = not good.
Based on your numbers and my experience, you will be alright to operate normally the rest of your trip.
I installed a new chassis vanner and new chassis batteries, all group 31 diehards in May of 2009. Without even using that built in 24 volt charger, these batteries have to this day never failed.
Appropriate testing to diagnose what is needed is above my pay grade.Oh, I trust that your routine includes shutting off the main 12 and 24 volt breakers when you are parked for one day or more. Not doing this aggravates the balance.
I live one hour east of Blackhawk, so if you need me, call 8478943868.
Got the 911 GTS (spec: 3.8 seconds, 189) two weeks ago, still in break in, hard to restrain myself.
-
Explain how shutting off the 12 and 24 volt master switches affects balance?
In 25 years the only time I have shut mine off on any of my three coaches was when I was servicing something.
-
Since I don’t know how to attach a pic, I will just quote here from page 133 of the Liberty Coach owners manual 1994.
” Note: When the coach engine will not be run for more than 2 days, the engine battery cut-outs should be switched off. This will help the coach batteries to stay equalized. Turning off the disconnects will not affect any of the house electrical systems.”
Why? I may never know.
-
At the monitor inputs, i’m still 27.5 and 12.5. So it sounds like there is a problem with the Equalizer.
What 12volt systems on the chassis are there to be aware of?
Thanks! This seems logical to me.
-
Some would be head lights, tail lights, radio, cigarette lighter, and I think those digital clocks in the bedroom and center front dash. Be vintage sensitive.
-
We should be home before dark. This might impact the brake lights though, they could get dim.
We don’t use the cigarette/cigar lighter.
The radio/naviation device appears to be tied to the house batteries.
The digital clocks (which I have to reset everytime I turn the chassis batteries off), I’m not too concerned about.
Is there anything else could be adversely impacted during a 2 hour drive?
Keep the advice and counsel coming! Thanks
-
Made it home without any apparent incident.
Before we left BFR I fired up the coach to warm it up I noticed that a light I normally see on the Vanner Equalizer was not on … at least in the bright sunlight I couldn’t see it was on. The label next to the light says something like the light indicates there is a load on the system.
When we got home it was dark, still no light. I still had the coach running to spin the turbo down so I turned on all the possible chassis lights to create a 12volt load. Still no light on the Vanner Equalizer. I presume this means something isn’t good with the Equalizer.
-
I think your vintage will have a fuse on the bottom of the equalizer. Worth checking. The light should indicate a balance problem.
Your 12 volt does handle coach lighting, but the most critical function is DDEC.
-
My BAT light has been on since I bought the coach. No telling how long it had been on before, as the previous owner had black electrical tape over it. Have checked all inputs and all are in range. New batteries last year. Never caused any problem other than the light being on, so I just keep on running it. Eventually, the culprit will present itself.
-
Does your vintage coach have the Vanner monitor?
-
Always shut my switches off in engine compartment even on overnight trips to campgrounds. having said that, had a couple bad New POS chinese batteries I installed in house bank go bad and light would come on and off until I replaced them. Hasn’t come back on in a couple years since replacement. I guess charging system (Vanner’s) running down road detected the bad battery.
-
Jon, It does have the monitor. All readings are correct there, as per your instructions early on.
My bus has two Vanners. But only one is hooked up, which may be part of the reason for the light. But everything seems to work. One of the Vanners is the old 60 amp style. This is the one that is unhooked. The other is the newer 100 amp style.
As for cutting the batteries off… I never cut mine off when I am on a trip. But when I get home to park for a week or so, I’ll cut them off.
-
If the input values to the Vanner monitor are within the allowable range it is probable the monitor has failed. A new monitor will make the light go out unless you do have an issue.
It is a worthwhile device that should be in working order because a warning light gets your attention. It is not necessary if you monitor you gauges closely, but if you are working in heavy traffic that is not always possible. In that case I am thankful for the monitor because a low battery voltage or imbalance is an inconvenience, but high voltage can have serious consequences and even a few minutes at a runaway high chassis voltage can do a lot of damage.
-
Thanks. Where is the best place to get a new monitor?
Log in to reply.