HI-LO Battery Light

[tdelorme]

Friday night as we were running up I35 into Arkansas, my hi-lo battery light flashed a few times. Then today we we headed home it came on and stayed on all the way back. I wasn't real worried about it because the dash volt gage is still showing about 27 volts. Called Joe and he agreed that getting home would not be a problem, which it wasn't. So, what's going on? I guess I need to disconnect all the batteries and check each one, but if anyone has another idea I'd sure like to hear it. Thanks

[garyde]

Hi Ted. When my batteries went bad , my regulator went bad also.

[Loc]

Ted,

You were lucky. When my Hi-Lo voltage light came on I continued to drive after a conversation with a shop in Houston that said it should be okay. I destroyed all of the house batteries and chassis batteries. In my case the voltage regulator was bad.

Loc

[truk4u]

Mel,

You could have a battery problem, but also check the alternator output while running and then check the equalizer by putting a meter on the 12v lead and then the 24 volt lead. They should be within a 1/2 volt of each other. As an example; on the 12v side 13.3 X 2 = 26.6 and the 24 volt side may be 27, a difference of .4 volt.

Also, don't discount the monitor that's wired to the equalizer, mine went bad turning on the hi/lo light and the monitor was the culprit.

[Jon Wehrenberg]

Mel,

If you have voltage in excess of 14.2 (28.4) you have reason to be concerned. Those voltages are with the engine running and the alternator putting out power.

Conversely, if you see voltages approaching 12.0 (24.0) with the engine running your batteries are just about depleted.

With the hi/lo light on just verify your voltage at the batteries and equalizer are matching what your dash gauge says and if it is within that range above you can still drive. The low voltage obviously is because the alternator has ceased putting out power and if you have one you need to be running your auxiliary charger. If the voltage exceeds the voltage listed above that excess voltage has the potential to do some serious damage, and in that case you need to disable the alternator, either by removing its belt or removing the field wire from the voltage regulator.

This is one topic we will discuss in detail in Spearfish. It is covered in information sharing under Prevost Electrical Systems and that will be expanded upon after the rally with pictures and probably some more text.

[Steve Bennett]

We had a similar problem last year. The Hi/Lo switch would come on & off, but the volt gauge showed 27V steady. It was a Vanner control unit. I believe it was $80.00 or so. It is located in the rear engine compartment, on the fire wall.

[tdelorme]

Steve, is this the controller your talking about. I think these are the battery equalizers. Four of them and they all test good.


If there is another Vanner controller, a better description and location would help. My batteries all tested good after being disconnected overnight. A call to Prevost service also mentioned the Vanner controller and said no problem driving the coach if the dash voltmeter stayed below 29 volts.
Still searching for the problem, but so far everything checks out ok.

[Steve Bennett]

Ted, I gave you some wrong info. It is located in the rear electrical panel above the engine where your relays & rear junction box is. Mine was at the top of the inside panel. It is about 6" X 4" and is called a Vanner battery monitor.

[merle&louise]

Ted,

You were lucky. When my Hi-Lo voltage light came on I continued to drive after a conversation with a shop in Houston that said it should be okay. I destroyed all of the house batteries and chassis batteries. In my case the voltage regulator was bad.

Loc

I'll bet I can guess which shop told you to drive home!

[tdelorme]

Thanks, Steve. I found the Vanner controller right where you said and ordered one from Prevost today. I went ahead and started removing the old one. The neat thing about the unit is that it has a power LED light that shows if it is working or not. My light was out until I got it unattached and then it started flashing and then stayed on. As long as the power light is on, the HI-LO battery warning light is blank. If the controller power light is out the warning light is on, so I think the new unit will fix my problem.
Here is a picture of the Vanner Battery Controller that is attached inside the engine compartment electrical box at the top.