2021 Isata 3 generator question

icbill · 09-19-2021, 08:29 PM

The diesel generator on my recently purchased I-3 shuts the batteries off when I try to start it. I have to plug into AC power to get it started. I push the gen on button and in 15 or 20 seconds when I get the voltage and gen off readout I push the start button and the starter turns briefly and then everything goes dead. So I plug the AC cord in and I can start it up no problem. What am I doing wrong?

Bill Davis · 09-20-2021, 07:24 AM

I sounds like your house battery’s are dead or the cable connections are loose or corroded.

SeaDog · 09-20-2021, 08:22 AM

X2 with checking he coach batteries and connections let the forum know what you find.

icbill · 09-20-2021, 01:12 PM

I’ve checked the battery connections and they seem good. They are lithium batteries and the voltage reads 13.7.

**bclemens** · 09-20-2021, 02:38 PM

Quote:

Originally Posted by icbill

The diesel generator on my recently purchased I-3 shuts the batteries off when I try to start it. I have to plug into AC power to get it started. I push the gen on button and in 15 or 20 seconds when I get the voltage and gen off readout I push the start button and the starter turns briefly and then everything goes dead. So I plug the AC cord in and I can start it up no problem. What am I doing wrong?

Now that I have read this back, it makes a little more sense.

1. IF you plug in and start it, then the diesel gen is not really taking a load. Shore power will power everything...so the gen is running at idle.

2. When you said it "shuts off the batteries" it is not shutting off the batteries it is just shutting down and you are losing 110V power. (and in change over, the 12V just needs to be turned back on)

I think I know what the issue is. We had a dealer recently have a similar issues. Diesel gen would not run for more than 20 minutes. They took the fuel line for the gen and put it into a fuel tank and it would run. Back to the chassis it would not. We check the lines and found no restrictions, kinks, etc.

There happened to be an Onan rep on property who gave us some info and we tested his theory.

“When these aren’t run for a while, the fuel lines (and maybe more importantly the return lines) will sometimes empty of fuel. The pump has a harder time keeping up (will cut off under load). The best thing to do when running this for the first time, is to start up the chassis engine and let it run for a bit to make sure all the fuel lines are filled. Then fire up the generator”

We did this, shut off the chassis, and the generator has been running for about 45 minutes now, with no issues. When we asked him about the gen repair place hooking it into an alternate fuel source he said…

“well, running through the fuel lines to the chassis tank is a longer run than feeding from a fuel tank and there is not as much drag on the pump”

icbill · 09-20-2021, 02:40 PM

Ok I think the batteries were low. It charged all night on shore power. Just now I checked all of the connections I even went under the rv and checked the main ground. Then I tried to start under battery power only and it started! New coach learning curve. Thanks for the input.

bubbles · 09-20-2021, 02:59 PM

“When these aren’t run for a while, the fuel lines (and maybe more importantly the return lines) will sometimes empty of fuel. The pump has a harder time keeping up (will cut off under load). The best thing to do when running this for the first time, is to start up the chassis engine and let it run for a bit to make sure all the fuel lines are filled. Then fire up the generator”

I think this is posted in the wrong section.

**bclemens** · 09-20-2021, 03:11 PM

Quote:

Originally Posted by bubbles

“When these aren’t run for a while, the fuel lines (and maybe more importantly the return lines) will sometimes empty of fuel. The pump has a harder time keeping up (will cut off under load). The best thing to do when running this for the first time, is to start up the chassis engine and let it run for a bit to make sure all the fuel lines are filled. Then fire up the generator”

I think this is posted in the wrong section.

No, right spot (sort of). I read "Gen would not run", was multi-tasking and missed that it would not even start.

SO, maybe it will help someone else with a "gen question" still

Edit: OR, if now that it starts, it only runs for 20 minutes or so, I have precognitively provided the answer in advance of ever hearing the question.

bubbles · 09-20-2021, 03:31 PM

Quote:

Originally Posted by bclemens

No, right spot (sort of). I read "Gen would not run", was multi-tasking and missed that it would not even start.

SO, maybe it will help someone else with a "gen question" still

Edit: OR, if now that it starts, it only runs for 20 minutes or so, I have omnipotently provided the answer in advance of ever hearing the question.

The fuel delivery plumbing for an Onan gen is not in any way associated with the vehicle main fuel plumbing. The gen has its own dedicated fuel line/pump and prime. The only thing common is the fuel tank.

**bclemens** · 09-20-2021, 03:37 PM

Quote:

Originally Posted by bubbles

The fuel delivery plumbing for an Onan gen is not in any way associated with the vehicle main fuel plumbing. The gen has its own dedicated fuel line/pump and prime. The only thing common is the fuel tank.

Not arguing with you, just passing on what the Onan rep said and when we tried starting the chassis first, it worked (where it had not at the dealer).

Also, in looking at the connection, unlike others, at least one of the lines is a "Y", not a direct tap to the tank.

sdbruin · 09-20-2021, 10:44 PM

It sounds like the original problem is fixed. Having the I3 + diesel gen now for the last year, among other learning curve oddities, we have also learned that the coach fuel tank should be a scoche more than 1/2 full, or it will only run for a bit then shut down by itself. Again, not what OP had an issue with, but was a surprise for us when dry camping.

Bill Davis · 09-21-2021, 06:18 AM

Quote:

Originally Posted by icbill

Ok I think the batteries were low. It charged all night on shore power. Just now I checked all of the connections I even went under the rv and checked the main ground. Then I tried to start under battery power only and it started! New coach learning curve. Thanks for the input.

Your welcome, and welcome to the Dynamax family.

Larry-NC · 09-21-2021, 02:49 PM

Quote:

Originally Posted by sdbruin

It sounds like the original problem is fixed. Having the I3 + diesel gen now for the last year, among other learning curve oddities, we have also learned that the coach fuel tank should be a scoche more than 1/2 full, or it will only run for a bit then shut down by itself. Again, not what OP had an issue with, but was a surprise for us when dry camping.

It's a safety feature. It keeps the generator from sucking the tank dry and leaving you stuck in the woods.

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