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Berjmobile's avatar
Berjmobile
Explorer
Jun 15, 2015

Start up electrical fault

I got a problem that has me over a stump! I have a '93 Pace Arrow diesel on an Oshkosh chassis. For the first time in 15 years of ownership, I was faced with a situatiuon where there was a power loss during start up. It goes like this: Put in the key, twist to start, lights come up for less than a second, lights flicker including the Allison indicator and go out and engine fails to turn over. Coach is dead on the road! A new attempt begins 5 minutes later: put in key, twist to start, lights come on, the Allison indicator shows neutral, engine starts. So far this scenerio has occured about 5 times over one weeks time. The ONLY recent electrical work was a conversion to LED house lighting. Talked to the folks at La Mesa RV and they said they no longer have anyone who knows Oshkosh chassis electrics. All batteries (house & chassis)are fully charged and all the connections are clean and tight. I give up!! Any members got a suggestion(s? Thanks for any replys. Jim
Class A

7 Replies

  • wa8yxm's avatar
    wa8yxm
    Explorer III
    Jun 15, 2015
    Jagtech wrote:
    Still sounds like a flakey battery connection. Have you checked the ground cable at the frame connection? Also, a bad engine battery can act like that if it has a bad connection between cells (internal fault). It will still charge and check as good.


    My original coach battery made it about 9 years before I had to replace.

    During that time the O/P's description happened 4 times

    And every time the quoted text described the problem.

    The first 3 I crawled under with load tester Disconnected a lead Hooked up the tester and confirmed GOOD BATTERY cleaned connections and re-attached and fired that sucker up like new

    The forth time the load tester confirmed BAD BATTERY and a brand new DEKA appeared in the battery tray. (And fired that sucker right up).
  • wolfe10's avatar
    wolfe10
    Explorer
    Jun 15, 2015
    Could be the ignition solenoid. Easy test: When this happens, does the dash HVAC fan (assume it only runs when ignition on) run?

    If not, locate the ignition solenoid (probably up in the dash area or perhaps in the forward most basement compartment in front of the driver's wheel on some coaches).

    Use your digital voltmeter to check voltage on each of the two large lugs. With the key on, both large lugs should read the same as battery voltage and 12+ VDC.

    This is a fairly high failure rate item. And as they age, the contacts can fail-- work sometimes, not others.

    If this is it and you need to move it, let us know. There is a "work around".
  • Hank_MI's avatar
    Hank_MI
    Explorer
    Jun 15, 2015
    Tom/Barb wrote:
    Sounds to me like you have a high resistance connection in the negative side of the battery to frame/engine. do a voltage drop test at each connection see where the connection is loosing ground.

    It is making ground until you place a load on the connection.

    Yes, these can be intermittent.


    Why do you say negative side? A bad connection on either side will act the same.
  • Tom_Barb's avatar
    Tom_Barb
    Explorer
    Jun 15, 2015
    Sounds to me like you have a high resistance connection in the negative side of the battery to frame/engine. do a voltage drop test at each connection see where the connection is loosing ground.

    It is making ground until you place a load on the connection.

    Yes, these can be intermittent.
  • gemert's avatar
    gemert
    Explorer
    Jun 15, 2015
    Batteries! Take the chassis batteries to an auto store and have them load tested then probably buy new ones. Replace both at once.
  • Jagtech's avatar
    Jagtech
    Explorer
    Jun 15, 2015
    Still sounds like a flakey battery connection. Have you checked the ground cable at the frame connection? Also, a bad engine battery can act like that if it has a bad connection between cells (internal fault). It will still charge and check as good.

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