Fussy Generator July 28, 2018, 01:37:23 pm Apparently my air conditioner doesn't like the heat. It starts and runs just fine when temperatures are moderate. But when the ambient temperatures are hot, it starts OK, but shuts down after about 5-10 minutes. It runs great on the coast (where I don't need it) and inland after the sun goes down!Anyone else have this problem? (And yes, there's gas in the tank and oil in the genset.) Is this normal, or is it time for an appointment at Cummins?Lorna,in not cool Washington.
Re: Fussy AC Reply #1 – July 28, 2018, 03:04:24 pm Hi Lorna,Is your question about your air conditioner OR the generator?If your genset is shutting down, there should be a code blinking on the display panel that can be referenced in the Onan manual.Steve K.
Re: Fussy AC Reply #2 – July 28, 2018, 04:06:55 pm Lorna, a Cummins Onan shop won't be of any help if the problem is with the AC and not the generator. (Is the generator working OK to power other 120VAC needs?) Maybe the condenser and evaporator on the AC are dirty/clogged? You might want to look for an RV service center!
Re: Fussy AC Reply #3 – July 28, 2018, 04:24:53 pm Lorna, when I was researching air conditioners I found in product descriptions that we all should have a 3500W generator to run standard rooftop air conditioners. While it might work with ssmaller generators it will strain both the generator and the air conditioner (shorteneing their life span), What watt is your generator and which air conditioner model (and model number) do you have?When our air conditioner (30 years old) started showing problems - the relay was shorted - it would shut down the generator after a couple of minutes but run fine on shore power. I might guess the condenser is working much harder in the heat and your generator is not 3500 watts so turns itself off (to protect the generator) when the air conditioner is pulling too much power.
Re: Fussy AC Reply #4 – July 28, 2018, 04:29:12 pm Lorna, are you trying to run from the generator? If so, do you have the same problem with shorepower?Steve
Re: Fussy AC Reply #5 – July 28, 2018, 05:27:59 pm Hey Steve K ... long time...! My bad...thread should have been titled "Fussy Generator." (Chris, any way to change that?)The generator is a Micro Quiet with over 950 hours on it (don't now what watt; it's factory supplied, as is the AC) and has been serviced by Onan at specified intervals. The issue is not the AC.; AC runs fine on shore power. And the generator works fine when it's not hot. When it's hot, it functions for ten minutes or so before shutting down no matter what appliance is in use. Perhaps at its age it's just having hot flashes?!!!Lornaon the road in WA, paused at a bead store!Thank y
Re: Fussy AC Reply #6 – July 28, 2018, 05:40:25 pm Quote from: Lorna Dunham - July 28, 2018, 05:27:59 pmHey Steve K ... long time...! My bad...thread should have been titled "Fussy Generator." (Chris, any way to change that?)The generator is a Micro Quiet with over 950 hours on it (don't now what watt; it's factory supplied, as is the AC) and has been serviced by Onan at specified intervals. The issue is not the AC.; AC runs fine on shore power. And the generator works fine when it's not hot. When it's hot, it functions for ten minutes or so before shutting down no matter what appliance is in use. Perhaps at its age it's just having hot flashes?!!!Lornaon the road in WA, paused at a bead store!Thank yJust a thought here. If this just started and is with all appliances you may be experiencing low oil shutdown
Re: Fussy AC Reply #7 – July 28, 2018, 05:48:56 pm Lorna, Cummins Sales and Service in Sumner might welcome the challenge!
Re: Fussy AC Reply #8 – July 28, 2018, 07:11:24 pm LornaHave the generator rubber fuel lines been replaced?Your 2003 LD is the right age to have had old fuel line installed at the Factory, like so many other LDs of the vintage.The fuel line used in 2003 was old stock, our lower fuel line started leaking within two years.Rotted lines suck air, instead of fuel . You have the usual symptoms of the generator dying after running a few minutes.The problem is probably worse when the fuel level is less than a 1/2 tank.Larry 1 Likes
Re: Fussy Generator Reply #9 – July 29, 2018, 12:36:35 am Just an experienced guess but the fuel pump overheats and fails temporarily in hot weather. Replace the fuel pump.
Re: Fussy Generator Reply #10 – July 29, 2018, 03:22:22 am Has the generator's rubber fuel lines been replaced yet.2003-2004 LDs are notorious for having these lines rot and leak air. The Factory installed old stock, our 2003's lower generator fuel line starting leaking after just two years.The upper was replaced a few years ago.Typical symptom, the generator will start but only run for a few minutes before stalling.One test is to use a small gas can and a length of good fuel line to bypass the rubber lines, to see if the generator runs normally.Larry
Re: Fussy AC Reply #11 – July 29, 2018, 02:57:31 pm Quote from: Sawyer - July 28, 2018, 05:40:25 pmJust a thought here. If this just started and is with all appliances you may be experiencing low oil shutdownFirst thing I did was check the oil level; it was fine. Also, fuel lines on this 2003 were replaced years ago. Now the fuel pump...? That would indeed be worth checking out.Thank you all for your suggestions. Fortunately, there is a Cummins shop nearby; an appointment is in my future. However, unless it's super hot out where he tests it, this may be an exercise in "stump-the-tech"!!Lornastill hot in WA!
Re: Fussy Generator Reply #12 – July 29, 2018, 03:49:36 pm https://www.flightsystems.com/pdf/onan-rv-troubleshooting-guide.pdf 1 Likes
Re: Fussy Generator - FOLLOW UP Reply #13 – August 03, 2018, 03:42:59 pm I spoke by phone with a nice tech support man from Cummins, thankfully negating the necessity of taking my rig to a service center. He said the genset was probably shutting down in extreme heat because only hot air was circulating through the engine; hot exhaust was going back into the engine causing it to overheat and shut down. Although there was a lack of cool air to cool the engine, it's likely no harm was done. Should I have wished to pursue the issue, I could take the rig in and have Cummins perform a "Hot Air Circulation Test," but since the generator worked fine as the ambient air cooled, he did not believe that test was necessary. 2 Likes