Forum Discussion

catkins's avatar
catkins
Explorer II
Sep 09, 2015

Tiffin diesel mysteries..............

2015 Tiffin Red diesel with Cummins engine and Allison tranny. All going well until I took in for 15k service at Freightliner.

I had seen a dash Low Battery warning once upon starting. Diagnosed as bad batteries (after 13 months??) Replaced. Now, something still is drawing down the batteries even when the battery cutoff are turned to off. 5-7 amps and fluctuating with phantom draws. More than I have seen before.

When I did start the engine, it did this weird sequential ramp up of idling speed. MOved by itself from 1000RPMs to 1800 Rpms before I hit the brake pedal to force it down to 1000RPMs

FYI - I have 800 watts of solar panels, controller and a trickle charger for the chassis batteries in additions to the charging of the house batteries. All compounding finding the issue, I Suppose.

Headed back for service but I am not knowledgeable and these guys do not seem to know so much...............

Supposed to be leaving this weekend. Not happening now. Need help!! Any ideas for what to get checked???

Electrical and water are my two least favorite issues to have. Thanks for any ideas.

Thanks for any bright ideas.
Class A
  • HD8100A's avatar
    HD8100A
    Explorer
    Sep 09, 2015
    Are you getting a low voltage battery level indicator on the dash for the engine/chassis battery? Do you see this when the temperature outside is colder? Our Allegro Bus also gets a low engine/chassis battery voltage level on the dash at colder temperature at start-up and the engine increases the idle to compensate for the voltage level ( increase amperage output of the alternator). Per Tiffin who my mechanic contacted it is the engine heater that kicks in ( forget how many watts it pulls) this may be the cause of the voltage draw on the engine/chassis battery but if would only be at start up. I also have seen this even after having new batteries installed. Did not install batteries due to this just switched them out since I wanted AGM batteries.
  • catkins's avatar
    catkins
    Explorer II
    Sep 09, 2015
    It was near 70 today so was not a contributor. Real puzzle is draw down when everything is off including battery switches for house and chassis. Sound like something electronic has gone wacky. Low battery was on dash. New batteries, draw down and message below 12v.
    Ugh
  • DSDP_Don's avatar
    DSDP_Don
    Explorer
    Sep 09, 2015
    You need to look to see what is connected to the batteries BEFORE the shut off switch. You could have an issue with your solar power controller. Disconnect anything connected before the switch and see if you can eliminate your battery issue.
  • sch911's avatar
    sch911
    Explorer
    Sep 09, 2015
    DSDP Don wrote:
    You need to look to see what is connected to the batteries BEFORE the shut off switch. You could have an issue with your solar power controller. Disconnect anything connected before the switch and see if you can eliminate your battery issue.


    X 2
  • jplante4's avatar
    jplante4
    Explorer II
    Sep 09, 2015
    Check the engine hours meter. Should not be running if the engine is off. Some of them have an oil pressure switch that fails causing them to run all the time.
  • accsys's avatar
    accsys
    Explorer
    Sep 09, 2015
    Also the Battery Minder is known to draw current from the battery when you do not have shore power. It will drain it in not too long a time. Most of us have replaced it with the Trik-L-Start or Amp-L-Start to keep the chassis batteries charged whenever you have shore power.
  • mccsix's avatar
    mccsix
    Explorer
    Sep 09, 2015
    My Entegra/Cummins DP used to start with high amp draw because the intake heater automatically cycled on at start and drew a LOT of amps,
  • Ivylog's avatar
    Ivylog
    Explorer III
    Sep 09, 2015
    I would go on my trip... just unhook the engine batteries when you get there. Do not rely on the disconnect switch as it does not disconnect everything.

    As for your problem, I would start at the starter solenoid as there is usually a wire feeding the starting circuit and even the dash. With the engine batteries disconnected using a 3/4" wrench take this wire off and then see if it's the 5-7 amp problem... hook the batteries back up and test.
  • mabynack's avatar
    mabynack
    Explorer II
    Sep 09, 2015
    One technique I've used to isolate problems is to pull the fuses one at a time and put an ammeter across the terminals in the fuse box. There should be little or no current flowing across the fuse terminals. If you get a reading across one, you've identified which circuit is giving problems.
  • fourmat's avatar
    fourmat
    Explorer
    Sep 09, 2015
    is that 5-7 amp draw on chassis battery that is pretty hefty draw chassis battery shouldn't last a day with that draw.

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