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matho22 · 03-08-2019, 03:43 PM

Hi, I have a 2011 Tiffin Allegro Bus 43 QGP. I parked it for some weeks in Seattle WA and now I can't start it anymore. It seemed the batteries were empty and I asked another guy with a pickup Truck for a jump start.

I checked the battery power when my coach was connected to the pickup Truck, it had 16.5 volts, but even with that volts, I could not start my Cummins. I heard the engine cranking but not long enough to start.

Before I tried the jump start I charged my batteries overnight, got 14.5 volts in it, but the same, could not start the Cummins. Any idea what I did wrong? I was wondering when I got 16.5 volts from the pickup Truck why I couldn't start the engine.

Many thanks.

oscarvan · 03-08-2019, 04:41 PM

Quote:

Originally Posted by matho22

Hi, I have a 2011 Tiffin Allegro Bus 43 QGP. I parked it for some weeks in Seattle WA and now I can't start it anymore. It seemed the batteries were empty and I asked another guy with a pickup Truck for a jump start.

I checked the battery power when my coach was connected to the pickup Truck, it had 16.5 volts, but even with that volts, I could not start my Cummins. I heard the engine cranking but not long enough to start.

Before I tried the jump start I charged my batteries overnight, got 14.5 volts in it, but the same, could not start the Cummins. Any idea what I did wrong? I was wondering when I got 16.5 volts from the pickup Truck why I couldn't start the engine.

Many thanks.

Did you try the emergency start switch?

A fully charged lead acid battery which has been at rest at room temperature for an hour or so will give 12.6 volts, no more. What you were reading was the battery charger and the alternator of the pickup truck. (Which is a little high btw.) This all tells you NOTHING about the state of charge of your batteries.

Neither is enough AMPERAGE to crank a heavy diesel. (That's why you have two HEAVY DUTY batteries.)

You either need to get an HEAVY DUTY battery charger on there (30-40 amp or preferably more) for quite a few hours (like 5-6-7+) or you need to jump using HEAVY DUTY cables from a HEAVY DUTY 12V supply.

Suggest calling a mobile truck repair service.

If it was me I'd get a set of heavy duty jumper cables, parallel the house and chassis batteries and run the generator for a few hours to charge ALL your batteries to a decent level. Your inverter charger puts out quite a few amps. (100 if it has the Magnum which the 2011 manual seems to indicate)

If indeed you have the 2028 Magnum with a remote you'll be able to see the progress. When the amps going in start dropping into single digits you can try it.

Since it's in the low 30's up there at night I would run the block heater to make it easier for the engine to turn over and start.

Then use the emergency start switch so ALL of it is pushing the starter.

FleetMan · 03-08-2019, 04:49 PM

Do you have road service as part of your MH insurance?

matho22 · 03-09-2019, 12:16 AM

Thanks Oscarvan, when you say emergency start switch, do you mean the "AUX" switch which also use the house batteries to start the engine? If so, yes I also tried this, but without success. Tiffin installed a batterie conditioner to my starter batteries and I thought that would be enough to charge them, but when I understand you correctly, it needs much more power to get them back to life, right? About the amperage, I tried to figure out what amperage my starter batteries provide, so I would buy a decent jump starter, just in case, what do you think?

matho22 · 03-09-2019, 12:18 AM

.Thanks Oscarvan, when you say emergency start switch, do you mean the "AUX" switch which also use the house batteries to start the engine? If so, yes I also tried this, but without success. Tiffin installed a batterie conditioner to my starter batteries and I thought that would be enough to charge them, but when I understand you correctly, it needs much more power to get them back to life, right? About the amperage, I tried to figure out what amperage my starter batteries provide, so I would buy a decent jump starter, just in case, what do you think?

Kennzz05 · 03-09-2019, 12:47 AM

Depending on the age of your batteries if they sat dischargedfor any length of time they are toast no amount of charging is going to help them they just simply cannot develop the amperage needed to turn the motor over to the proper rpm that the ECM needs to see for the motor to start
On the larger Cummins ISX Motors the ECM needs to see 125 RPM while cranking in order to start if your engine is turning over the least bit slowly it will never start you need new batteries

Kennzz05 · 03-09-2019, 12:53 AM

What was the outdoor temp when you were doing this? It just occurred to me and your diesel may be gelled

oscarvan · 03-09-2019, 05:47 AM

Quote:

Originally Posted by Kennzz05

What was the outdoor temp when you were doing this? It just occurred to me and your diesel may be gelled

He's in Seattle.... overnight temps in 30's. Gelling not an issue. Plus, it's not turning over. First you need it spinning then we talk fuel.

Peter M · 03-09-2019, 06:02 AM

The consensus suggests the batteries are dead. Just buy new and be done with it.
OP how old are the current batteries ?

Kennzz05 · 03-09-2019, 06:18 AM

Quote:

Originally Posted by oscarvan

He's in Seattle.... overnight temps in 30's. Gelling not an issue. Plus, it's not turning over. First you need it spinning then we talk fuel.

It is in fact turning over

Kennzz05 · 03-09-2019, 06:19 AM

N/m

sirtate · 03-09-2019, 08:55 AM

It's likely the batteries.

As mentioned earlier; if the engine doesn't crank fast enough, it won't start.

Big diesels don't use glow plugs, they use the compression of cranking to ignite the fuel.
While a little automotive diesel will use a glow plug to heat the top of the combustion chamber, or a heater grid across the intake manifold to heat the air going into the engine, most heavy diesels don't.

They just spin them fast enough to make the heat by compression.

If your battery bank is weak you just won't have the ooomph to do the job when the ambient air is cold.

Have you tried it with a snort of ether? (That really is a two person job)

Ivylog · 03-09-2019, 09:31 AM

Big Diesel engines need additional heat when it’s really cold (below freezing) and while it may not be glow plugs, on a big Cummins it’s a on electric grid heater in the intake. Without this extra heat, it’s not going to start, regardless of how fast you spin it.

Jumping with a PU is not going to do much unless the cables are welding cables...500+ amps and even then it can take several minutes to get enough power into the weak batteries to spin it fast enough to start.

I buy starting fluid by the case (it’s not ether any more) but you need to be careful to not give it too much. There is some concern that the grid heater might set it off prematurely.

Ilvmygt · 03-09-2019, 09:34 AM

Consider removing the batteries and taking them to a battery shop to have them charged and load tested. That would be the best way to determine the condition of the batteries.

Also clean the battery connections. You will lose a lot of voltage with bad connections.

Are these the original batteries?