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

[catkins]

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.

[catkins]

OK - will keep that in mind. "They" say they cannot replicate the problem................ maybe the replacement batteries were installed with a low charge and now are working. I will believe it when I see it but would like to be able to leave soon.

Thanks to all the helpful thoughts and ideas!

[GPWayne]

On my Cummins. First start of the day idle goes from 800 to 1000 rpm, low battery for 3 - 4 minutes (12 V. engine heater) then up to normal for the rest of the day.

I would guess your engine heater control is not turning off the heater as it should.

[catkins]

All seems to be operating normally but somewhere, something is amiss. Keep the ideas coming - like I said in the shop but maybe one of you out there is support land will have the magic answer.

I also wondered about something being stuck "on" that should turn off when I shut down. Solar appears to be working correctly. And the yet puzzle remains. Thanks all.

[wolfe10]

jax1911 wrote:
Is your engine block heater plugged in?,

The block heater is strictly 120 VAC.

And, were the intake manifold heater (it is 12 VDC) stuck on (bad relay, etc), it would draw well more than the amps mentioned.

[jax1911]

Is your engine block heater plugged in?, If your inverter is on you will see 2 or 3 amp draw from it.

[catkins]

Agree, not an survivable draw when unplugged. My brand new batteries are throwing that Low Battery message when I first start up when there is a huge draw as stated here. Issue seems to be as suggested before the battery cutoffs............ No thought at local Freightliner to look at WHY the batteries died at 13 month. Hmmmmmmm

Is now in a different shop and someone smarter than I am is looking into it all. I appreciate all the ideas and will make suggestions to the "experts" in the shop if they fail to find the culprit. You guys are the BEST source of info. Appreciate it. I generally fix things with a screwdriver, duct tape and checkbook and checkbook has been recently flattened.

My nightmare is this is a short/frayed wire and can take forever to solve. Thanks all for your shared wisdom!

[wolfe10]

fourmat wrote:
is that 5-7 amp draw on chassis battery that is pretty hefty draw chassis battery shouldn't last a day with that draw.

Yup, that is way more than an acceptable "Parasitic Draw".

[fourmat]

is that 5-7 amp draw on chassis battery that is pretty hefty draw chassis battery shouldn't last a day with that draw.

[mabynack]

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.

[Ivylog]

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.

[mccsix]

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]

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]

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]

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.

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