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 1000RPMsFYI - 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.

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.

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

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.

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

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.

Tiffin diesel mysteries.............. | Good Sam Community

17 Replies

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,
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.
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.
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
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.
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
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.

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

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