Has anyone seen this happen?

[MrTransistor]

Hi All,
We have an 04 Horizon WD40 on the Freightliner XC Series chassis with CAT C7 350 HP engine. Out of the corner of my eye, I occasionally catch the Volt gauge dropping to zero then returning to 13.2 volts or so. I have watched it like a hawk for many miles and it won't do it. Then I'll catch it again. It only drops to zero for a second or two and there seems to be no repeating pattern to it. No other abnormalities like dimmed lights at night or movement of other instruments occur when this happens. It's just an extremely odd quirk and it would be nice to know if this is something that is normal in the Freightliner software. Has anybody observed this?

[MrTransistor]

Hi All,
We have an 04 Horizon WD40 on the Freightliner XC Series chassis with CAT C7 350 HP engine. Out of the corner of my eye, I occasionally catch the Volt gauge dropping to zero then returning to 13.2 volts or so. I have watched it like a hawk for many miles and it won't do it. Then I'll catch it again. It only drops to zero for a second or two and there seems to be no repeating pattern to it. No other abnormalities like dimmed lights at night or movement of other instruments occur when this happens. It's just an extremely odd quirk and it would be nice to know if this is something that is normal in the Freightliner software. Has anybody observed this?

["007"]

Mark, maybe you have a loose ground cable some where on frame or a fuse panel and vibration is causeing a momentary open. "007"

[MrTransistor]

Hi 007,
Already considered. We've been on incredibly smooth highways and wash board dirt roads that rattle your teeth and I see no difference. And as I say, there are no other instruments affected and no dimming of any lights indicating that the alternator actually did drop off line momentarily. I have not observed it to occur at idle but it happens so infrequently I wouldn't expect to. On a 250 mile trip, I may notice it 1 to 3 times.

["007"]

Do these things have regulators now adays. "007"

[MrTransistor]

Hi 007,
Yes they do, electronic, in the alternator. When our coach was new, almost two years ago, we lost an alternator driving through Minnesota. Symptoms were low voltage indication on the dash meter. Freightliner replaced the alternator no questions asked. Then when we hit the eastern panhandle of West Virginia, we seemed to have had another failure. Symptoms this time were intermittent voltage too high. Turned out to be a broken B+ sense wire cause by too much stress during the first replacement. Freightliner in Hagerstown, Md. fixed the connection and we've had no problems since.