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jswat
Explorer
Sep 09, 2014

Diesel Generator Start

We left home (Texas) on Sunday (9-7) for a trip to Knob Knoster State Park in Missouri. My coach (2004 Holiday Rambler Ambassador) had been on 50 amp shore power. When I tried to start the generator, it would turn over but not start. After an hour of driving in the Texas heat, pushed start and it fired right up. My question, would low house batteries keep the geny from starting? I think it may be time for new batteries, they are dated 08.
  • Mine starts very slow after it has not been used for a long period of time. Be nice if it would kick off after one push of the switch.
  • YUP! As for batteries 6 years is old enough. Get new ones. If batteries are low on ours the slider moans and groans.
  • if you're on shore power (or the generator) - the converter/charger output should take care of rolling that awning all the way up (quicker) than on (low) batteries.
  • To answer replies so far: my generator is an Onan Quiet Diesel, 7500. It has never failed to start, until this trip. My house batteries have never been boiled dry but they do test a bit weak. Not surprising since they are more than 6 years old. When I tried starting it, it seemed to be turning over a bit slow. After we drove for an hour, it spun normally and fired right up. I believe the generator starts from the house batteries. Incidentally, my awning is also slow to come in and will not retract all the way without help. I believe this indicates weak house batteries. Am I right?
  • bshpilot wrote:
    FIRE UP wrote:
    Well Sir,
    First off, what model, model number, gas, diesel, what? Has it EVER done this before? Has it been starting normally each and every time you've needed it, up to this incident? And, you said it cranked but, didn't start. That's not really a sign of bad batteries. If any battery was bad, it wouldn't crank. Need a bit more info to try and help here.
    Scott


    If my batteries are switched off, the generator engine will turn briefly but not enough to start.
    if the battery voltage is low it could act similarly !


    A similar situation happened to us too a few years ago. One day while traveling we stopped at a rest stop for lunch and wanted to run the house air so we needed to start the generator.

    It would turn over but not start (it did sound slow trying to turn over). Our genny is connected to the chassis batteries. The engine would start fine but not the genny. Once the engine was started, the genny would start normally. The service shop determined that the chassis batteries were low. I had the two chassis batteries replaced once we returned home and all was well with the world.

    MM.
  • FIRE UP wrote:
    Well Sir,
    First off, what model, model number, gas, diesel, what? Has it EVER done this before? Has it been starting normally each and every time you've needed it, up to this incident? And, you said it cranked but, didn't start. That's not really a sign of bad batteries. If any battery was bad, it wouldn't crank. Need a bit more info to try and help here.
    Scott


    If my batteries are switched off, the generator engine will turn briefly but not enough to start.
    if the battery voltage is low it could act similarly !
  • Well Sir,
    First off, what model, model number, gas, diesel, what? Has it EVER done this before? Has it been starting normally each and every time you've needed it, up to this incident? And, you said it cranked but, didn't start. That's not really a sign of bad batteries. If any battery was bad, it wouldn't crank. Need a bit more info to try and help here.
    Scott
  • jswat wrote:
    We left home (Texas) on Sunday (9-7) for a trip to Knob Knoster State Park in Missouri. My coach (2004 Holiday Rambler Ambassador) had been on 50 amp shore power. When I tried to start the generator, it would turn over but not start. After an hour of driving in the Texas heat, pushed start and it fired right up. My question, would low house batteries keep the geny from starting? I think it may be time for new batteries, they are dated 08.


    absolutely ! the generator (usually) is started via the house batteries.

    your converter/charger should have been keeping the batteries "topped up" while it was connected to (50A) shore power.

    it would be worth checking the house batteries to see if they've been boiled dry.