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AL49er's avatar
AL49er
Explorer
Sep 19, 2013

Charging and then discharging going down the road

I have a 2004 motor home with 330 cat when going down the road the AMP hand will discharge for 2 or 3 miles and start charging 13.8 .
What could causes this? any help pleas.
Can a louse grown wire cause a volt meter to charge and discharge when going down the road?? Thanks.
NO LITES ARE NOT ON.
  • Hi every one, well I did find my charging problem when the service man put the alternator he forgot to put the grown wire back on.
    To all who help me thanks. Al.
  • AL49er wrote:
    I have a 2004 motor home with 330 cat when going down the road the AMP hand will discharge for 2 or 3 miles and start charging 13.8 .
    What could causes this? any help pleas.
    Can a louse grown wire cause a volt meter to charge and discharge when going down the road?? Thanks.
    NO LITES ARE NOT ON.


    I found the grown going from the jennerater to the frame was luse
    clend and tighton works grate. Thank to all of you for helping
    tahnks agin.
  • AL49er wrote:
    Can a louse grown wire cause a volt meter to charge and discharge when going down the road?? Thanks.


    Sure, loose connections can cause all kinds of issues-- on either ground or positive side.

    And a loose ground on the dash gauge can also cause false readings, even if the voltage is stable between alternator and batteries.

    Easy to test the dash gauge. Wire your digital voltmeter to a cigarette lighter plug and monitor voltage at that outlet vs dash gauge. Not as accurate as a reading at the battery, but a lot easier to do.
  • Can a louse grown wire cause a volt meter to charge and discharge when going down the road?? Thanks.
  • OK what are you calling discharging in light of rgatihnet1 post.

    If a battery is charging at 13.8 (good) and drops back to 12.6 that would not be discharging in my view. If it goes to 12.4 or less than it would be in my view. My Scan Gauge II will stay on for a few seconds reading the battery voltage with the engine shut off. If it is 12.6+ I know all is well.
  • Sounds pretty close to normal for me. I have an OBDII ScanGuage and "charging voltage" is one of the things that I continuously monitor. The voltage regulator will switch to charge the batteries and then shut off so as not to overcharge and destroy the batteries. How often the regulator switches depends on how much current you are drawing from your battery. My system charges at 14.4 volts and drops to 12.6 when not charging. It has been doing this for several years and the battery is doing fine.
    You may want to check your batteries to make sure that they have enough electrolyte but I think your system is operating as it should.
  • Could be your air intake heater which is normal when the engine is cold. It will cycle on and off until engine is warm and draws a lot of current off the charging system.
  • AL49r,
    You say you have an '04 coach with the 330 CAT, correct? May I ask, what coach, brand/make/model etc. just in case it's like ours, an '04 Itasca Horizon, 36GD with the C-7 330HP CAT and the Allison MH3000 trans. And, another question, do you have any sub systems in the dash that display redundant information on any other screen? The reason I ask is, in our Horizon, we have at least two more sub systems that display pertinent information. One is called the "Trip-Tek" information system and the other is called the Medallion Information Center".

    I only say all this because if you have any other system besides your standard "Voltmeter" on the dash that will display volts, (not amps) not many coaches are equipped with ammeters, then you could compare the readings to see if your gauge is on the fritz or not. Good luck.
    Scott
  • Sounds like the voltage regulator device is flaky perhaps. Where the head lights burning?