OT Standby generator problem I created need help

Copperhead don't play · Dec 22, 2017

Guardian 15,000 watt house standby generator"s battery was too weak to start the generator. I had indicator lights, 12 volt power, everything except enough juice left in the battery to start. So I connected the battery charger and THEN I went to start it and NO NOTHING. NOW I have no indicator lights, no nothing. No attempt to start.
I replaced the battery, checked the 5 and 15 amp fuses in the control panel, and still no nothing. No indicator lights, no attempt to start. Just like there was no battery at all. What did I mess up?

Crazy Horse · Dec 22, 2017

I guess this goes without saying ...... you did not disconnect the ground strap from the battery right? Not that doing so would cause an issue, people charge car batteries all the time without disconnecting cables. Hopefully, someone will be able to help you out.

old · Dec 22, 2017

Start with the simple stuff and check all battery cable connections. Did you by chance hook it up backwards is in + where it should have been - if you did you may be looking for a new generator.

showcrop · Dec 22, 2017

Sounds like a bad cable connection. When you put the load on it and it tries to carry the full current that the starter draws, a poor connection is likely to suddenly arc. Once it arcs in the connection it has produced carbon which changes the poor connection to no connection.

Bob Harvey · Dec 22, 2017

Ummm. Is this an old unit ? Do the people that provided the equipment have a phone # ? This is a good place to ask ?? Hope it works out for you. Best of the season to you and yours.

jm. · Dec 22, 2017

Well I sure do not want to be the bearer of bad news BUT when that happened to my neighbors he had to have the control board replaced. SOMEWHERE IN THE OWNERS MANUAL it cautions again JUMP starting. The thing has a built in charger and most likely it was a connection problem not weak battery. He had his installed after we had our put in and my battery had never gave any problem but after that I put a new one in. My unit is now 7 years old now and no problem. Hope you have a good dealer to call.

Billy Shafer · Dec 22, 2017

If the battery was changed with the charger still on. It is possible to knock out the control board.But there are other things that could have gone wrong. I sent you an email.

grizz02 · Dec 22, 2017

had a onan gen set go out same way I had it on a charger and tried to start it knocked out the brain box cost 3500.00

Steinkamp sales · Dec 22, 2017

Try cleaning your battery terminals. Most likely just bad connection.

WGM · Dec 22, 2017

Manual? Who needs a manual?

MarkB_MI · Dec 23, 2017

Hmm. If the battery was in good shape but just discharged, hooking it up to a charger shouldn't have caused any problems. But if the battery was bad, it's POSSIBLE the charger generated enough voltage to fry something in the control board. Honestly, the beast should be designed to handle a reasonable overvoltage, but this is a Generac.

You replaced the battery, presumably with a known good, fully charged battery. Time to break out the voltmeter to see where you're losing power. You may not be able to troubleshoot the control board, but you should be able to verify you have good voltage to the board and starter relay.

Texasmark1 · Dec 23, 2017

Get out your voltmeter and check for voltage at the terminals where it's used in particular....which checks battery, cables, and all connections inbetween.

Making and breaking connections as such generate arcs which could/would generate voltage transients that can overpower any protective circuitry. Wouldn't doubt that somewhere in the owner's manual was a caution against such usage. You said the 5 and 15 amp fuses.

My circuitry on a 11k Generac uses a 7 ? amp fuse for circuit board operation and protection which is located up on top where the controls are located, and the item that is to be removed (aka open circuit power to the circuit card controller) before any kind of maintenance is done to the unit. How did you check the fuse for continuity?

Copperhead don't play · Dec 25, 2017

If this is a double post I apologize, it didn't go thru the first time.
Thank each and everyone of you who gave advice on my problem.

One member, a 40 year generator technician, even emailed me and walked me thru the problem on the telephone. Even told me about a reputable company who could repair my board.
I had connected my battery charger and on a very weak battery it puts out 19 or 20 charging volts which melted a tiny metal strip on the back of the control board. Yes, the manual states remove the two (5 and 15 amp) fuses before jumping or charging the battery. I only read the manual after I made this mistake. I had called the company who installed the unit and got a very young and inexperienced guy. Who kept telling me to replace the 12 volt battery even after I told him repeatedly I had installed a new battery and there were no indicator lights on.
Again thanks for the help. You guys are a great bunch of people.

kcm.MN · Dec 25, 2017

Yup, that Billy Shafer is a pretty sharp cookie! :wink:

OT Standby generator problem I created need help

Copperhead don't play

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Crazy Horse

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old

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Steinkamp sales

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