Generator Woes, Onan nhe emerald + 6500

Malfunctioning transfer switch is my suggestion, probably when hitting a bump it jumps free.

Thanks for that suggestion, I am going to check it out!

eldondo,

Not sure if your Onan is similar to my Emerald 7kw model (gas), but mine seems to be VERY sensitive to oil level and oil viscosity. If the oil level is low OR if the oil is thin, mine will do what your describe. I believe that when you hit a good bump, the oil sloshes around and the oil pressure sensor sends a signal that the oil is low, the generator begins to shut down. This immediately cuts off the AC power. If the sensor then sends an "oil is OK" and the engine is still spinning, it'll keep on running. But the AC power won't be restored until about 30 seconds later when the timer kicks it on. I listen for the microwave to beep indicating power is back. If I don't get the beep, then I restart it.

I now run straight 30W oil in it (per Onan's oil viscosity recommendations) as I don't generally run it in the very cold temps. (IF I knew I wanted to do winter camping, I'd drain it and put in some thinner stuff.) I used to run one of the multi-viscosity oils they recommend year-round, but then I would notice the issue quite frequently, ESPECIALLY when running in the summer heat.

So, check the oil recommendation chart for your generator and try using the thickest, single viscosity oil recommended for the temperature range expected.

Good Luck,

~Rick

P.S. I also assume you know that once the fuel level in the tank starts getting down around 1/3-1/4 tank mark, the generator pick-up tube may not get a steady supply of gas, and that might cause your problem as well. So make sure you have enough gas in the tank. :)

May be something in here... Onan Troubleshooting Guide

Thanks for the assistance from each of you. I am going to order a new starter for it and put it on myself, I hope, if I can squeeze in there as my mechanic did. Then I am going to unplug the electric power cord. Then I am going to start the generator. Warm it up, turn on the air conditioners and hang out in the rv and hope something occurs that I can trace down or observe something that I can do something about.

Rick Jay, I reread your post again and I could almost think that is what is going on with mine except mine stays off for several minutes and then all of a sudden here it comes the air conditioning starts blowing cold. I don't know how in the world you figured out that was your problem. From inside the rv I can't hear the generator while I'm going down the road. I do thank you for that information.

Yes those oil sensors are touchy. I have a nhm and I had parked my horse trailer in a different spot one time and it was pretty high in the front . I tried to start that gen for a week had the carb off all kind of stuff finally realized how out of level it was leveled it and the gen started right up man did I feel dumb.
When you run a gen while your driving your taken a chance of it dying with a load on the gen it can knock the VR out. Like when you pull out of a store and hit the big drainage dip it can put the trailer off tilt pretty good. Just have to be careful.

eldondo wrote:
I reread your post again and I could almost think that is what is going on with mine except mine stays off for several minutes and then all of a sudden here it comes the air conditioning starts blowing cold.

First, is the AC blower off entirely during those few minutes, or is the blower on, but no cold air? The AC's have a timer on them as well that keep them from restarting the compressor for several minutes after a shut-down to allow the refrigerant pressure a chance to equalize throughout the system so the motor has an easier time of starting. The fans, however, will continue to blow air IF you have the blower set to "On". (My systems has an "On" and an "Auto" position.) I think that if you have the system set to "Auto", the blowers may not come on either, until the system times out. So that might be what you're experiencing with the several minute delay.

Way back when, when I originally diagnosed this problem, the TV would cut-off with the generator, so I'd know right away. Then wifey would have to turn on the TV, turn on the DVD player, cue up the DVD to where it stopped...so much work...a regular suburban domestic tragedy! LOL Anyway, I noticed that it happened most frequently on a.) very hot days and b.) if it had been a while since I checked the oil level. Note, the oil level was never "low" by way of the dip stick, just not right up to the fill mark. We run our generator pretty much any time we're rolling to keep the ACs running. So I had numerous opportunities to observe the problem.

After doing a lot of reading, mostly on these forums, I realized that the oil switch is finicky. Changing to the thicker, single viscosity oil and making sure it's at the "full" mark every time before I hit the road really minimizes the problem. It will occasionally happen, but it's pretty rare now and it has to be one heck of a bump.

As far as staying in the rig and waiting for it to happen while parked...well...if it IS an oil/oil switch related issue, the problem won't happen when you're stopped.

I'd recommend taking a regular old incandescent lamp (mechanical on/off switch) or night light, plug it into an outlet and turn it on. Fire up the generator and go drive over some bumpy roads. If you see the light shut off, then turn on about 30 seconds later, you know it's most likely oil related.

Someone mentioned that the transfer switch might be loosing it's connection. While that's possible, I know that wasn't my problem. I did have a transfer switch failure and have had to replace mine, but it didn't have any effect on the situation I was experiencing.

Some additional info, which may or may not be helpful to your situation: I do have a light on the generator switch at the driver's position which lights when the generator is running, which is helpful...except you can't really see it in most daylight without shielding it. Anyway, the TV/DVD player has been replaced with an LCD screen & Macmini computer on a UPS. The videos they watch have been ripped from the DVD, so we have eliminated all of that hassle. But wait...now with new technology...they all have their own iPad...so it's rare for them to even watch the TV while rolling down the road. Ahhhh....technology saves the day! LOL

Anyway, good luck with your issue.

~Rick

Rick Jay wrote:

eldondo wrote:
I reread your post again and I could almost think that is what is going on with mine except mine stays off for several minutes and then all of a sudden here it comes the air conditioning starts blowing cold.

First, is the AC blower off entirely during those few minutes, or is the blower on, but no cold air? The AC's have a timer on them as well that keep them from restarting the compressor for several minutes after a shut-down to allow the refrigerant pressure a chance to equalize throughout the system so the motor has an easier time of starting. The fans, however, will continue to blow air IF you have the blower set to "On". (My systems has an "On" and an "Auto" position.) I think that if you have the system set to "Auto", the blowers may not come on either, until the system times out. So that might be what you're experiencing with the several minute delay.

Way back when, when I originally diagnosed this problem, the TV would cut-off with the generator, so I'd know right away. Then wifey would have to turn on the TV, turn on the DVD player, cue up the DVD to where it stopped...so much work...a regular suburban domestic tragedy! LOL Anyway, I noticed that it happened most frequently on a.) very hot days and b.) if it had been a while since I checked the oil level. Note, the oil level was never "low" by way of the dip stick, just not right up to the fill mark. We run our generator pretty much any time we're rolling to keep the ACs running. So I had numerous opportunities to observe the problem.

After doing a lot of reading, mostly on these forums, I realized that the oil switch is finicky. Changing to the thicker, single viscosity oil and making sure it's at the "full" mark every time before I hit the road really minimizes the problem. It will occasionally happen, but it's pretty rare now and it has to be one heck of a bump.

As far as staying in the rig and waiting for it to happen while parked...well...if it IS an oil/oil switch related issue, the problem won't happen when you're stopped.

I'd recommend taking a regular old incandescent lamp (mechanical on/off switch) or night light, plug it into an outlet and turn it on. Fire up the generator and go drive over some bumpy roads. If you see the light shut off, then turn on about 30 seconds later, you know it's most likely oil related.

Someone mentioned that the transfer switch might be loosing it's connection. While that's possible, I know that wasn't my problem. I did have a transfer switch failure and have had to replace mine, but it didn't have any effect on the situation I was experiencing.

Some additional info, which may or may not be helpful to your situation: I do have a light on the generator switch at the driver's position which lights when the generator is running, which is helpful...except you can't really see it in most daylight without shielding it. Anyway, the TV/DVD player has been replaced with an LCD screen & Macmini computer on a UPS. The videos they watch have been ripped from the DVD, so we have eliminated all of that hassle. But wait...now with new technology...they all have their own iPad...so it's rare for them to even watch the TV while rolling down the road. Ahhhh....technology saves the day! LOL

Anyway, good luck with your issue.

~Rick

Yes, Rick Jay. I am pretty sure the power goes off everywhere, I can't remember exactly how I determined that, but, I remember sending
my wife back to check this and that, feel this and that, etc. Now, what I think I found out last year was this. Ok, the generator was running, air conditioner blowing cold air and the red light on the dash was lit. Now, if I remember right, the air stops blowing out of the air conditioners, I look at the dash and the red generator light is off. I stopped and went outside and realized the generator was running but not producing any electricity. I drove on down the road and after a few minutes the air conditioners come back on spontaneously. It didn't happen all this smoothly because, at some point I thought the generator needed to be restarted and while I was flying down the road I mashed the starter button for a bit, which I think ruined the starter motor (my second). I am going to replace the 10w30 oil with 30weight asap. Replace the starter motor which I can buy online for 40 bucks and give it a test run in mid May. I thank you for your detailed and helpful post.

"I ruined my starter motor on the genset before I realized what was happening"

All right, I admit it, I'm dumb. How did a ruined starter motor get into the puzzle?