Generac Generator

It does sound like low voltage to the battery that the generator is connected to. While the engine is running then the alternator is putting out 13.5 volts (or more) and that will allow it to start quickly. It will be a expensive mechanic call to have them tell you the same thing, if nothing is wrong with the battery. Yet if you have a defective battery, the mechanic might be able to tell.

sounds like (house) batteries are low to me....especially when you consider you were able to start the generator w/ the coach running (most coach engine/alternators charge the house batteries when the coach is engine running)

Id put a voltmeter on the (house) batteries w/ everything turned off & see what the charge level is, my bet is you're gonna show low voltage.

couple of choice if the (house) batteries are low (v) - run the generator (to charge the batteries), connect to shore power so the converter/charger can charge the batteries or drive/run the coach so the engine alternator can charge the (house) batteries.

if the coach has been connected to shore power then i don't know why the battery voltage would be low - unless you've been cranking not he generator starter a bunch or your converter charger is not charging the (house) batteries.

Since you have a mechanic coming out. I'll wait until he does his thing. Until then it is only guessing.

Sure does sound like house batteries. You should have a booster switch beside the ignition that will borrow power from the chassis batteries while you start the generator. You have to hold the switch down. It a momentary switch.
You should also check the water level in the batteries. If they are low, that can cause then to not hold a charge. Fill with distiller water only and just cover the plates. Don't overfill.

Sounds as if you have the dreaded Generac starter problem. Mine had 985 hours on it when I got the MH,used,and started right up,for a month or so. Then it started doing what you're describing and then nothing. Took it in to the shop and he said the Bendix was melted to the starter and the starter actually looked pretty new. Found in the P/O records that it only had 20 hours on the gennie since it had been changed,but P/O hadn't put down the name of the shop. We changed the starter 3 times before we found one that lasted more than 10 starts. The last one lasted a year and now has started doing it's slow turn and finally a click. I redid the grounds and it didn't do any good. I did discover that my 4 y/o batteries were toast and so got 4 new 6v and still no good. Battery boost crossover doesn't do any good either nor having the engine running.While trying to recharge the old house batteries,they wouldn't take a charge from either the onboard charger or my 25amp aux charger, I slid under the front and hooked the battery charger to the gennie cables and after 6 hours it went from full 25 amp charging to a 5 amp charge and I tried to start it with the charger still hooked up and a 75amp push from it. Nope... No good. I am going to try disconnecting the battery cables to the gennie and just hitting it with the 75 amp starting boost from the charger. When I don't know as I'm in the middle of a bathroom emergency rebuild. The Dw decided that since I was redoing the totally plugged galvanised drain pipe and had the vanity off the wall,that now would be a good time for new flooring,vanity,toilet and wainscoating on the wall. Kinda over my head,but I'm actually muddling thru it towards a sucessful and neat ending.

Bigdog wrote:
Sounds as if you have the dreaded Generac starter problem. Mine had 985 hours on it when I got the MH,used,and started right up,for a month or so. Then it started doing what you're describing and then nothing. Took it in to the shop and he said the Bendix was melted to the starter and the starter actually looked pretty new. Found in the P/O records that it only had 20 hours on the gennie since it had been changed,but P/O hadn't put down the name of the shop. We changed the starter 3 times before we found one that lasted more than 10 starts. The last one lasted a year and now has started doing it's slow turn and finally a click. I redid the grounds and it didn't do any good. I did discover that my 4 y/o batteries were toast and so got 4 new 6v and still no good. Battery boost crossover doesn't do any good either nor having the engine running.While trying to recharge theold house batteries,they wouldn't take a charge from either the onboard charger or my 25amp aux charger, I slid under the front and hooked the battery charger to the gennie cables and after 6 hours it went from full 25 amp charging to a 5 amp charge and I tried to start it with the charger still hooked up and a 75amp push from it. Nope... No good. I am going to try disconnecting the battery cables to the gennie and just hitting it with the 75 amp starting boost from the charger. When I don't know as I'm in the middle of a bathroom emergency rebuild. The Dw decided that since I was redoing the totally plugged galvanised drain pipe and had the vanity off the wall,that now would be a good time for new flooring,vanity,toilet and wainscoating on the wall. Kinda over my head,but I'm actually muddling thru it towards a sucessful and neat ending.

Bigdog are you installing aftermarket Generac starters?

I think it's got an aftermarket in it now,but it worked out the same for all of them. I had a couple of each. The first two weree Generac starters and then the third one was an aftermarket and the one in now is also an aftermarket. Yes,it does still have a warranty,but that's only for a new starter and not the labor to change it.

Checked my chassis batteries and they were all good
(Over 13.8) my 6 volt house batteries were all over 6.7
Like I said before when the starter was first installed it started
right away . Then it started clicking and dragging .
Then read that some were starting with engine running so tried that
and the generator started, did that couple times. Looking at getting someone
with more experience. I think the starter is defective.

Just because your batteries are reading 12+ volts does not mean the amps are getting to your starter to turn the engine over. It sounds to me like you may have corroded connections at the battery or the generator end because your generator turns over with the eng running. To know for sure I would connect a battery or battery from your tow car directly to the generator. If it starts you have a problem in the cables from your house battery to the genset. If it does not start then I would look at the starter.

Okay,went up this PM and slid under the front end of the MH with my wrenches and battery charger. Discovered that the 50 amp CB had blown and so no problem disconnecting the cables from the gennie. Hooked up the battery charger to the gennie leads and it showed no battery and wouldn't put out any power to the gennie. It's one of those B&D 25 amp chargers with the analyzer and a 75 amp engine start. I rehooked it up to the battery and reset the CB and the charger showed bad atteries,sulfated or dead cell,and the gennie still turned over slowly and wouldn't start. Had to reset the CB and that sucker was really HOT. OOppss.Oh and the batteries are brand new 6V a couple of weeks ago.
Got a couple of suggestions from an RV tech and another guy I know and they both suggested that I drain some fuel from the gennie supply line as it's probably been there for awhile since the gennie hasn't wanted to start for about 6 months.