Low Voltage Alarm

[BobD]

I was wondering if anyone has had a problem with the alarm going off indicating that the coach engine is only putting out 9.7 volts instead of the 14.6 it usually does.
My motorhome is a class A 33'Winnebago Adventurer on a Workhorse chassi.
I have had it in the shop for repair and they cannot find the problem. Any help with this problem would be appreciated.
BobD

[BobD]

I was wondering if anyone has had a problem with the alarm going off indicating that the coach engine is only putting out 9.7 volts instead of the 14.6 it usually does.
My motorhome is a class A 33'Winnebago Adventurer on a Workhorse chassi.
I have had it in the shop for repair and they cannot find the problem. Any help with this problem would be appreciated.
BobD

[troth]

BobD, we could use a bit more info. What year is the coach? Has it "always" been like this? Is it at a Workhorse service center? Sounds like the alternator is giving up. We're here to help, 'er speculate, whichever...

[BobD]

Hi Last Brave,
My coach is a 2004 Winnebago Adventurer
33' on a Workhorse chassis. We were on our way home and the buzzer just came on and I drove it home and took it to S&J Chevrolet who are Workhorse Chassis approved shop. They are having problems finding the problem. I to think it is the altenator because it says it is only putting out 9.7 volts and it should be at 14.6.
I hope the additional information will help, never had the problem before this and the coach only has 4200 miles on it.
BobD

[troth]

Well BobD, welcome to irv2 and I'm sure others will chime in here to greet you... Offhand, I'd say let's have the Workhorse shop do their diagnostics and advise. But please keep us posted on what they find (or don't find)... There's a lot of good advice and data in these forums.

[BobD]

Thanks! will let everyone know the out come.

[BobD]

Hi Last Brave,
I said I would give an update on the low voltage on my 2004 Adventurer saga and now they indicate it is not the altenator as it checks out fine. They are now somewhat stumped as the gauges and alarms remain on after the key has been turned off. They are looking for an answer now. So far nothing has jumped out at them and they are in contact with the Tech's at Workhorse as well.
That's it for now maybe someone has had a similiar problem. I would love to hear from them.
BobD

[Gary RVRoamer]

Are you sure it isn't an inverter that is giving the alarm? I don't have a Winnie, but have never had a low voltage alarm in my W22 Workhorse. Just about all inverters, however, give low voltage alarms and it would be independent of the ignition switch. A low voltage alarm from an inverter usually means a bad battery bank. You might hear the alarm only when you shut the engine down, since at other times the engine alternator would supply enough power to keep the inverter happy.

And a bad battery can drag down the voltage from the alternator too. I would think that would show up when they tested it, though.

[BobD]

Hi Gary,
Thanks for your suggestion about the inverter I will pass it on to the shop so they will be sure to check it out.
They are stumped as I said so any suggestion is appreciated.
I know when the alarm came on, on my trip home from San Diego I had the generator on and it still gave me the low voltage alarm so I'm not sure the inverter is the cause.
The one main issue now as I stated in the update is the alarm and gauges etc remaining on after you turn off the key and remove it.
It will run the battery down if allowed to.
Again my thanks for your thoughts.
This site is extremely helpful on many issues.
BobD

[Bob (WA0MQE)]

When you say "alarm" are you talking about the built in dash alarm that you hear when your low on fuel, or some other problem exists with the chassis?

Gary, mentioned the inverter, but that's not part of the chassis so this wouldn't show up on the "Workhorse Dash Alarm."

Your post indicates that it's putting out only 9.7 volts all the time. Is this true? If so, I wonder how they determined the alternator checked out okay.

The problem with most dealers and their mechanics is they don't really understand electrical/electronics that well. They can only check things according to a book. I'd make sure they disconnect the house batteries, and only check out the alternator in conjunction with the chassis battery. The coach batteries or something in the battery switching could be dragging it down.

[BobD]

Hi waOmge,
Thanks for the information.
Yes the actual output that the alternator reads out when the engine is running is 9.7. The shop said they used a meter to read the alternator output.
The alarm and guages, abs etc stay on now even after the key is turned off and removed.
I will ask the shop if they have disconnected the coach batteries and checked the alternator output.
Thanks for the information and any suggestion are appreciated.
BobD

[Gary RVRoamer]

As wa0mqe says, the iverter will not triger the Workhorse dash alarm. I was merely suggesting that you be sure which alarm is actually going off. I thought of the inverter since the alarm seems independent of the ignitionswitch.

Based on your further description of the problem, it sounds as thought here may be a dashboard wiring problem. If the alternator checks OK but the dash gauge shows only 9.7 volts, it stands to reason that something is draining off the voltage on the way to the gauge (or rather, the sensor that feeds the gauge). A short would do that, for example. Your gauge is digital, so the displayed reading is being provided by either by the ECM or a separate analog to digital converter somewhere. Need to find where it is getting the 9.7 volt data and begin looking there for a low voltage problem.

I assume the alternator is indeed putting out adequate voltage or your chassis batteries would go flat even while driving.

[BobD]

Thanks Gary,
I believe like you that there is a short somewhere between the alternator and the instrument panel. I'll talk with the shop tomorrow and make sure they check the ECM and look for the short.
BobD

[Gary RVRoamer]

Let us know what is found - or at least what else they check out.