Community Forums

bigdog · 08-11-2015, 12:14 AM

Got the starter motor replaced,again, and after running it a couple of times at home and running the A/C to work it,it quit putting out AC power. Have run it several times since then,when I was able to get it started,a problem for another day,and today I noticed that when I turned the A/C switch off, that there was a click coming from the area of my transfer switch. By the way, the A/C doesn't start at all and if you turn on the micro,it just barely runs.
It doesn't matter what position the linebreaker switch is in,it still just clicks as the A/C switch goes off. As was suggested in another thread, I did kinda smack the ATS with a rubber mallet to no avail..

Rook · 08-11-2015, 05:40 AM

Bigdog.....let's get some basics.....what is the specific series and model number of your Diesel Generac Genny? On my unit, this info is listed on the front panel of the Control Box mounted on the Genny. Rook

bigdog · 08-11-2015, 09:25 AM

Hi Rook, I have the generac Quietpac 75D. My guy says it's the board and to take it to a Cummins shop which is Freightliner around here and the guy at the Olympia store said that I need to take it to a D Square or a Square D dealer and the only one around here is 1/2 day away. I checked my Cornerstone service contract and it seems as if it would be covered.
I'm wondering if it might be the line breaker, but I'm wondering why I would get a click from the area where the ATS is located if that were true.

I'm also thinking that instead of something being wrong with the starter,it may be the heater or fuel pump system. The last couple of times I've started it, I hit the start button for about 5-10 seconds, let up and hit the heater button for 15 seconds, wait a little bit and hit the starter button and she'll catch. If I hit the heater button for the 15-30 seconds and then hit both as suggested,then it barely turns over and will usually blow the breaker.

John USA · 08-11-2015, 09:44 AM

I just repaired my Generac gas model. The electrical section between yours and mine is quite similar, and the troubleshooting flow charts follow same logic.

First step is to get the Generac running consistently. Until then, you can't effectively troubleshoot voltage output. The heater or fuel pump should not affect AC output.

Once it's running, you can determine if it is putting out voltage at the required frequency. Checks are made right on the generator, takes just a few minutes.

This will, effectively, split the troubleshooting in half. Either it's not putting out voltage, or the voltage it's putting out isn't getting to the coach.

For me, the first clue was the red LED on the voltage regulator was not lit up. Is your's lit up?

Arch Hoagland · 08-11-2015, 10:08 AM

https://www.generator-parts.com/manuals/generac-rv/0F4996.pdf

There's the manual.

Rook · 08-11-2015, 10:35 AM

Bigdog....ditto what John USA said, that's all good info. Sounds like you possibly have TWO separate problems..... one with the engine starting and the other with the Alternator. Like John said, you have to get the engine running BEFORE you can troubleshoot the Alternator. So, I highly recommend you do this to possibly "fix" your start/run problem. The Ginny starts using the house battery bank and it is LOOOOONG run, over 30 feet, from the genny to the cranking batteries. That makes it extremely important that all connections be tight, clean and with no corrosion.....that includes the ground at the battery bank to chassis metal and at the Genny to metal ground. So, near the house battery bank, find and then clean and sand/grind to bright metal, the MAIN chassis ground connection for the house battery bank. Then, do the same thing for the main genny ground to the metal chassis. then clean, lub all 12VDC connections from 12VDC feed line, at the genny, to the starter. that should help or fix your start problem. When you have done this, then we will tackle the Alternator if you are up to it. Rook

bigdog · 08-11-2015, 11:23 AM

That's all been done and like I said, I can get the gennie started ok, now that I have figgered that I can't hold the hate button and the starter button at the same time. Don't always ned the boost button either.

John, I didn't know about a red led. My gennie is in the front and totally encased in a cover. I can pull the front cover, but for major stuff, you've got to pull the gennie. I will go pull the front cover later and check for a light.

Arch,Thanks for the 100 page manual, I may just have to download it. Aren't you the guy that smokes those big cigars that was at one of our NW rallies a while ago?

Rook · 08-11-2015, 11:48 AM

OK, you can start the Genny and it runs normal......now that you have the Maintenance and Diagnostic Manual, a couple of other questions. 1) do you have a good Volt Ohm Meter (VOM)? 2) Do you know how to use it to measure DC and AC voltages and resistance and continuity? Number 2 will be a necessity to troubleshoot the Alternator. No point in getting started on the Alternator if we don't have that. Additionally, if you decide to NOT try the repair yourself, I recommend you find (GOOGLE) a Generac authorized repair facility to take it to. Rook

John USA · 08-11-2015, 07:56 PM

Page 68 & 69 of the manual. Item #3, is your regulator. Red light should be on when genny running.

Also, in addition to the above info from Rook, the meter needs to read frequency.

The troubleshooting guide directs you one direction if you have low frequency, another direction if you have low voltage, etc, so, it's important to check them both at the beginning.

If you head off down the wrong troubleshooting path, you could end up replacing a component unnecessarily.

Arch Hoagland · 08-12-2015, 12:04 AM

bigdog said:

"Arch,Thanks for the 100 page manual, I may just have to download it. Aren't you the guy that smokes those big cigars that was at one of our NW rallies a while ago?"

LOL...no that's not me, quit smoking about 40 years ago and hardly ever smoked cigars."

Don't go to rallies either....well, Quartzite but that's not really a rally.

bigdog · 08-15-2015, 09:52 PM

Well, have started the genie just fine the last three days. I hit the start button for 5-10 seconds and let up on it. Then hit the preheat/fuel pump button for 15 seconds and let up. Then hit the genie start button and she usually starts right up in a couple of seconds. I'm thinkin' that the preheat/fuel pump and start button combination is the culpert and is drawing too much current and overheating the breaker.
So now, on to the other problem, the AC output, or lack of same. I fired her up, notice the "her" reference, and pulled the front panel and found that everything was turning as it should, but I could not find any sign of any red LED. Looked all over everything I could see and just couldn't find even where it was if not lit. Shut her down and checked all the belts and they are new and tight. While she was running, I also hit the line breaker to check it both ways for power output. I'm hoping the there is power flowing with the switch in the up position.
I'm thinking that might try changing the line switch, before I take it all the way to North Bend to the Generac folks. From here that's at least a two hour trip up thru part of Seattle and out I-90..

Rook · 08-16-2015, 08:40 AM

Bigdog, your start problem, whatever it is, is in no way connected to your "no Voltage" from the Alternator. You can buy a decent Multimeter (VOM) at Lowes, Walmart or Home Depot for about $20.00. Its a MUST HAVE tool for any DIY person. Learning how to use it's basic capabilities is pretty simple. The FIRST measurement that needs to be made on the Alternator is it's output Voltage at the output breaker terminals. No voltage or very low voltage means an Alternator problem. If the Voltage is normal, 248VAC across the breaker, or 124VAC from one side to ground is normal. If the Voltage is present and normal, then your problem is in your Power Transfer Switch. You will have to open the Generator Control Box which is inside of the outside cover, to get to the backside of the Main Breaker to make the measurements.......that is also where the Voltage Regulator with the red LED is located. If you decide to do this yourself, BE CAREFUL....there are some lethal VOLTAGES in there when the Genny is running. You will save yourself some time and money by finding someone, locally, with the knowledge and skills to make these basic measurements. You may not have to take it to a GENERAC repair facility. Rook

Rook · 08-16-2015, 11:37 AM

Bigdog, your model Genny is physically different than mine and therefore some of the terms/names I used in my posts are different than on your Genny. For instance when I said "control box", on my Genny, on your Genny it is called "Control Panel" and it is located behind an "Electrical Access Panel". A good picture of your "control panel' is on pg 11 of the Manual (download from above link). Also the "Main Breaker" on your unit does not have to be removed to get at the place to measure the no-load genny output voltage. On your unit, this voltage can be easily measured between terminals T1 and T2 on the terminal strip just above the Voltage regulator. See all this on pg 11 of the manual. Rook

John USA · 08-16-2015, 03:39 PM

Yep, what Rook said. Look at page 11. If that looks like your's, then the voltage regulator is that square black thingy, with a red led. If it's lit up, you'll know it. Shines just like Rudolph's nose...if it's not it up...well, one step at a time...