# GENERAC 4109099 15000 Blows 15A Fuse



## tburk (Apr 23, 2021)

My GENERAC 15000W generator won't self test in automatic mode anymore. Manually it starts and runs great. But each time the exercise time is set the fuse blows before it can begin to crank over, but maybe the cranking starts and the fuse blows immediately so its hard to tell if it is cranking. I've already blown the old fuse, and 2 new ones and yes I replaced them with 15 amp fuses, although, the new fuse element looks thinner than the previous element. The unit has been self-exersizing for over a year now and this just started. Generator is out of warranty, and battery is 1 year old.

I read the manual but it doesn't help much in this instance at all.

How can I find what is wrong with this system?

Would this post by tabora apply to my system?:
the first thing to test would be the rectifier... Test 19 on Page 47 in this manual: http://pdfstream.manualsonline.com/0/0cbbf673-1de1-475a-9fe2-c70d8cdc7ae5.pdf

*Model Number:* 0051760
*Description:* 15KW GT990 TELECOM W/200A ATS 

Thank you.
Tom


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## Browse Deweb (Jan 16, 2021)

How new is your battery? A battery with lower voltage will pull more current on startup than one with higher voltage.


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## Old man here (Nov 5, 2020)

tburk said:


> My GENERAC 15000W generator won't self test in automatic mode anymore. Manually it starts and runs great. But each time the exercise time is set the fuse blows before it can begin to crank over, but maybe the cranking starts and the fuse blows immediately so its hard to tell if it is cranking. I've already blown the old fuse, and 2 new ones and yes I replaced them with 15 amp fuses, although, the new fuse element looks thinner than the previous element. The unit has been self-exersizing for over a year now and this just started.
> 
> I read the manual but it doesn't help much in this instance at all.
> 
> ...


Here are two excellent forums for Generac troubleshooting and repair:





Generac Generator Troubleshooting, Help, and Repair Forum | Gentek Power - Index page







gentekpower.com









Ziller Forum







www.zillerstore.com


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## tburk (Apr 23, 2021)

Browse Deweb said:


> How new is your battery? A battery with lower voltage will pull more current on startup than one with higher voltage.


Well it fires up quite nicely using 'Manual' option. I think it sounds strong I think its about 1 year old I bought it new.


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## Old man here (Nov 5, 2020)

tburk said:


> Well it fires up quite nicely using 'Manual' option. I think it sounds strong I think its about 1 year old I bought it new.


Is the generator or battery only one year old, is the generator still under warranty?


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## tburk (Apr 23, 2021)

Old man here said:


> Is the generator or battery only one year old, is the generator still under warranty?


The Generator is Long out of warranty, battery is about one year old. From what I understand, the 15A fuse protects the 12v DC board, so I'm wondering if that board is bad, or any of the wires leading to it or from it are shorted. I suppose I could inspect all the wires to and from that board, does anyone know location of that board?


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## Browse Deweb (Jan 16, 2021)

See this video:


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## tburk (Apr 23, 2021)

Browse Deweb said:


> See this video:


I'll give this a try this weekend and will let you know the results. Wondering if I can find my battery receipt. Hmmm...


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## tburk (Apr 23, 2021)

tburk said:


> I'll give this a try this weekend and will let you know the results. Wondering if I can find my battery receipt. Hmmm...


I tried this, got a new battery today, secured it in the generator, set the exercise time, and the 15A Fuse blew straight off. No cranking at all. I'm starting to think its the circuit board, not solenoid because it starts manually so strong very strong. I'm thinking I must replace circuit board, or find a shorted wire. Is there anyway Can anyone supply a diagram of the DC circuit board so I know what these wires are carrying and what their purpose is, and primarily so I know where the brains of the exercise control is located?

Again, thanks in advance.


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## iowagold (Jan 22, 2020)

walk through with a good meter and a test light!

and use a manual reset breaker!


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## tburk (Apr 23, 2021)

*UPDATE*

As originally posted, I bought a new battery straight away and installed, tested, and got same results. Inspected wires through out the system. Couple days ago I took that same new battery, charged it over 24 hours, re-installed, set exercise time, and the unit operated as expected. Looking back over the thread I see there are multiple suggestions on the battery charge/condition, that was the answer all along; lesson learned. Thanks to all for the consideration on this thread!


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## Browse Deweb (Jan 16, 2021)

Most whole house units will have a way to maintain battery charge without you having to install your own maintainer. You may want to look into this model's features and make sure that the battery maintainer function is working as intended. If not, you can either replace it or install your own maintainer so the new battery doesn't quickly get too low on charge.


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## iowagold (Jan 22, 2020)

in toms case.
an up grade would be in order.
by pass the old charger and use a modern charger with an 5 amp automatic breaker inline with the positive charge cable.
pm me for the details.


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