Generator not running

Topic: Generator not running (Read 1880 times) previous topic - next topic

Generator not running

May 15, 2018, 11:09:28 am

My turn for generator problems. 1999 U320 with PowerTech 10KW, 1888 hours.
Saturday while driving the coach the generator ran fine with both A/Cs running. After 3 hours it shut down, fault light on dash, NO fault lights on generator control box panel. Oil ok, coolant overflow low. Started up and it ran about 20-30 minutes and shutdown with same symptoms. Got to my storage and plugged in. Added coolant to overflow bottle. Checked generator, NO lights on control box panel. Started it up and it shut down in about 10 seconds. Breakers did not trip.
Today I checked the coolant level in radiator tank, OK, oil OK. Started up right away and ran with both A/Cs for about 15 minutes and shutdown with same symptoms. Fan is working. However when I started it up again the fuel pump did not click. Checked the connections on the connector at board and found the gray wire (schematic shows run solenoid and fuel) about half the strands broken off. Re-did that connection and check all others. BUT only have about 240 mV at fuel pump. Checked continuity of wire from pump to board connector and it is good.
Questions: first, does the electric fuel pump run continuosly while the generator is running? Or only at start-up?
Second, does this sound like the control board is bad? Or a bad relay?
Thanks!

Re: Generator not running

Reply #1 – May 15, 2018, 11:45:00 am

Would call Powertech and talk to their tech,alot of the time he is driving and does not mind helping out.

Re: Generator not running

Reply #2 – May 15, 2018, 11:50:20 am

12 volt lift pump should run anytime generator is running.

Re: Generator not running

Reply #3 – May 15, 2018, 01:44:41 pm

I was able to get a friend on the phone, he owns a generator shop. After discussing the issues it came down to either the relay or fuel pump. I changed out the relay and it fired right up! Been running for 30 minutes so far. I'll let it run a couple more hours, shut it down and start it up again. Then repeat over the next week or so to make sure there isn't another problem I overlooked.
Another question, is the fuel run/shutoff solenoid behind the generator? I don't see it on the front.

Re: Generator not running

Reply #4 – May 15, 2018, 02:36:11 pm

It should be on the front at the end of the fuel line rack, it is probably painted the same color as the engine.

Re: Generator not running

Reply #5 – May 15, 2018, 02:57:08 pm

Quote from: folivier – May 15, 2018, 01:44:41 pm

Another question, is the fuel run/shutoff solenoid behind the generator? I don't see it on the front.

Which power unit do you have? The Kubota is totally different than the Isuzu.

Mike

Re: Generator not running

Reply #6 – May 15, 2018, 03:49:32 pm

It is an Isuzu and just located the solenoid. Thanks.

Re: Generator not running

Reply #7 – May 17, 2018, 12:18:18 pm

Went to the coach today and pressed the start switch on dash, nothing. Tried starting from control panel on generator, nothing. Had 12+VDC to on/off switch so jumpered the switch and generator started normally.
However the run/stop switch is not doing anything and dash switch is not working. If I turn the on/off switch to off it will shut down, but when I turn it to on the generator will start up. I think the on/off switch should just power up the control panel circuits and the run/stop switch will start/stop the gen.
BTW I did test the low oil pressure by grounding it and engine shut down immediately and LOP light comes on, same for high temp switch and light on.

Re: Generator not running

Reply #8 – May 24, 2018, 08:33:40 pm

Still no success. Replaced the latching relay at suggestion from Jeff at PowerTech. Today I pulled the 2 relays on the control board and the 3 relays mounted in the control box and tested each with a 12volt power source. They all tested OK. Tested the 2 switches on control box and dash and bedroom switch, all tested OK.
Today after checking relays I ran the generator with load and it shut down after 1 hour with the low oil pressure, high temp, over crank, and overspeed alarms lit up. Oil & coolant is good. Started it up again and shuts down immediately. Then it started raining.
I need to slide the generator out more but the fuel lines are keeping it from coming more. Next chance I'll remove the lines and see if the generator will slide out enough for me to see inside of the control box.
I've been using a mirror. Possibly have a bad wire crimp?
I'm assuming the generator will only slide out so far and will not drop, right?

Re: Generator not running

Reply #9 – May 24, 2018, 09:18:31 pm

If you don't remove the stop, assuming it hasn't been removed previously, it will not fall out. I had to remove the stop to look at the back of the connection box on mine.

Re: Generator not running

Reply #10 – May 25, 2018, 12:40:57 pm

Got a couple more things to try next week. But if I can't at least get the generator running again who would be best to bring it to, MOT or FOT? Or is there anyone else in Nacog?
The engine and generator head appears to be operating properly it looks like there is a problem either with the control board or wiring.
So it seems like it would be best to get some place familiar with how FOT wired up the generator system. And this is assuming it's still wired up the way the factory built it.

Re: Generator not running

Reply #11 – May 25, 2018, 12:49:08 pm

You should be able to find a Power Tech approved shop a lot closer than Nacogdoches.

I would ask Jeff for his suggestion when you are ready to throw in the towel on doing this yourself.

Re: Generator not running

Reply #12 – May 28, 2018, 02:52:35 pm

Another update, after talking with my generator friend he is thinking it is a bad control board. All 5 relays test good, generator today ran ok for an hour then shut down. Started again and shut down within a couple minutes. Checked fuel solenoid and have 17amps dc at pull open, 1 amp at hold open. Interestingly the fuel pump has 12.5-13 volts at preheat but once generator is running it is only 6-11 volts and 1 amp at preheat then 0.4 amps to 0.9 amps. That has me thinking a bad control board also.
So tomorrow I'll start searching for a board.

Re: Generator not running

Reply #13 – May 28, 2018, 03:44:44 pm

Look on the Powertech site.

Re: Generator not running

Reply #14 – June 04, 2018, 02:30:31 pm

Today I replaced the ES52 board. Still doing same thing, when turn on/off switch to on it preheats and starts up, run/stop switch doesn't do anything. It ran 1-1/2 hours then shut down and overspeed led was flashing. Found a broken crimp ring connector for the white wire that goes to the speed signal on board. Black wire goes to hot (black) terminal on 120vac breaker, white wire to 1/4" bolt on back side of control box. Fixed that but still shutting down with overspeed led flashing (loss of speed signal). Even put in old board and shutting down in 3 seconds but overspeed led not flashing (could be burnt).
Could that white wire be connected elsewhere in control box? I did find what appears to be the ring terminal that is broken and matches the one on the white wire. The ES52 manual says these are NOT polarity sensitive but could that be the problem?
Looks like I will be bringing it to a repair shop soon.

Re: Generator not running

Reply #15 – June 04, 2018, 04:02:22 pm

I had a weird problem similar to yours a few years ago and it turned out to be a bad latching relay. It would shut down intermittently. Might want to verify you are getting a good connection on the latching relay or bypass it.

Mark

Re: Generator not running

Reply #16 – June 04, 2018, 04:32:59 pm

Foliver,
Here are the PowerTech service centers close to you.
John

Re: Generator not running

Reply #17 – June 04, 2018, 04:53:15 pm

On my kubota it did the same thing, it was the latching relay inside the control box. I don't know about Isuzu's.

Re: Generator not running

Reply #18 – June 04, 2018, 07:09:11 pm

FYI. This is the latching relay in my 99 Genest.

http://www.newark.com/finder/20-21-9-012-0000/contactor-spst-no-12vdc-din-rail/dp/08X7043

Mark

Re: Generator not running

Reply #19 – June 04, 2018, 07:55:20 pm

Already replaced the latching relay and didn't make any difference.
After talking with my generator friend we've narrowed the shutdown problem to low voltage at the fuel solenoid and lift pump. At preheat there is 13.5vdc but after gen. starts the voltage drops down to 6vdc at lift pump and on hold open terminal of fuel solenoid.
I also bypassed the controller by putting +12vdc on the gray wire, still shut down so this should put the problem between the controller and the lift pump and fuel solenoid. Since they both have the same low voltage it is either the wiring or relay or relay socket. The 40amp breaker feeding the relays is good.
Tomorrow I'll be testing the wires and relay sockets. Hopefully that will solve my problem of shutting down. Still have the problem with the run/stop and remote switches not working.

Re: Generator not running

Reply #20 – June 27, 2018, 09:23:53 pm

Well this is like the "never-ending story". Drove to FOT and had them work on the generator. On the drive up it quit and wouldn't re-start so I drove in the 90º+ heat. Alton found a broken wire that fixed the on/off run/stop issue. But it would still only run a few minutes before shutting down. No codes on controller. Even tried a new controller and still the same. After working on it all morning they determined the wires going to the relay socket were bad. I had looked at that and thought it was ok.
Finally got it working and I let it run for 5+ hours. Spent the night there and drove with generator running for 10 hours with 1 stop. Everything working like it should with 2 a/cs running.
But when I got home and pressed the dash switch to shut it off it didn't! Started doing the same thing. I did drive on some very rough and bumpy roads so possibly something jarred loose? Talked with Braxton today and they will discuss what it could be and call me later.
We leave on Sunday for a 6 week trip driving to Arizona, Utah, Colorado, and New Mexico. I'll probably end up running the generator like it is for now. If I can't fix it I'll stop at FOT on our way home in late August.
Frustrating!

Re: Generator not running

Reply #21 – June 27, 2018, 09:41:04 pm

mine would randomly die and after I changed the filters it worked properly and no issues.. doubt yours is as easy but Good Luck!!

Re: Generator not running

Reply #22 – June 27, 2018, 10:18:08 pm

Since your trouble apparently started with low coolant:

Procedure for bleeding the coolant system on Powertech Generators

Even if you do not have the same generator, this could be your issue. It was causing mine with similar time run symptoms.
Generator overtemp shut down

EDIT: I see your new issues are probably unrelated to coolant. Sorry about that. If you DO have a very small air pocket at the top, when it turns to steam it will overtemp the temp sender and shut it down.

Re: Generator not running

Reply #23 – June 28, 2018, 10:21:08 am

Success! Finally. Pulled the control box cover off and found a wire had come off of the latching relay. Replaced it and generator is working correctly now from the dash switch. Actually when I first turned the on/off switch on it started up like before. But I then remembered the latching relay had to reset. So used the run/stop switch and it stopped. Started, ran for an hour and stopped from dash switch.
Sunday will be the supreme test. Driving the same bumpy roads I did Tuesday. First stop will probably be at Buckhorn near Kerrville.

Re: Generator not running

Reply #24 – June 28, 2018, 06:22:29 pm

Quote from: folivier – June 28, 2018, 10:21:08 am

Success! Finally. Pulled the control box cover off and found a wire had come off of the latching relay. Replaced it and generator is working correctly now from the dash switch. Actually when I first turned the on/off switch on it started up like before. But I then remembered the latching relay had to reset. So used the run/stop switch and it stopped. Started, ran for an hour and stopped from dash switch.
Sunday will be the supreme test. Driving the same bumpy roads I did Tuesday. First stop will probably be at Buckhorn near Kerrville.

If the wire comes off again you can take pliers and squeeze the connector just a little to make it a tighter fit.

Affiliate Notice