View Full Version : generator power intermittant

06-02-2012, 01:49 AM
hi all,

michael day and i took my 2002 to the tire shop to get all new tires. it was 111 degrees today. the genny engine ran just fine. sitting still it has good power with no interruptions. as soon as you start driving the power goes off and then the transfer switch turns it back on 50 seconds later and then it will stay on for 5 min or so then do it all over again.

when we got home it ran for another hour with no stoppage of power. again, the engine ran fine.

when sitting i pounded on the transfer swithc, wiggled and shook the lines into and out of the trnasfer switch, slid the genny out and wiggled all the main wires out of the genny and no cut in electical power.

this is a real head scratcher and i can use your collective wisdom to solve it. please.


06-02-2012, 01:54 AM
Don't know if this will help, but I had a similar thing happen with my Country Coach. There was a junction box and the wires had come loose and showed up when the coach moved down the road.

06-02-2012, 06:27 AM
i am going to look in the morning. gotta get it fixed soon.



06-02-2012, 02:15 PM
Tom, I guess your trip to Ohio is coming on pretty fast now, huh? You will need that genset for sure to run the A/C with the heat and humidity you will be driving into. Glad I'm in the Pacific Northwest where it is cool, and a little rainy right now.

06-03-2012, 02:12 AM
Since vibration seems to not be an issue, I'm wondering if the intermittent problem is temperature related...maybe heat affecting a wire junction, the transfer switch, or a breaker in the gen. compartment? Try aiming your infrared temp sensor at the junctions, breakers, and transfer switches to see if there is a hot spot.

06-03-2012, 06:12 AM
today michael and i spent alot of time on the genny issue. we undid the genny slide and pulled the generator out as far as it would go using a 3 ton floor jack. had to take some stops off and you have to be careful so the genny doesnt land on your driveway.

checked the junction box coming out of the genny that couples it with the wires back to the transfer switch. it was ok. recrimped a few of them. then we checked the breaker box on top of the genny. found a wire bundle that was loose and tightened it up but dont think that was it. then i took the auto transfer switch loose and checked all the connections. also cleaned it out to be sure there was no loose wire strands.

everything checked out ok. we ran the genny for a couple of hours in the driveway and it didnt skip a beat. but....it did before as well. we might take a spin tomorrow after church and see if it still does it.

if it does, it has to be either the genny head unit itself, or the new transfer switch i put in is funky. not sure what else it could be.

still looking for any suggestions.



06-03-2012, 01:20 PM

Is the coil voltage on the new transfer switch the same as the old? Just trying to think outside the box, maybe the magnetic field is strong enough to hold the contact plunger in while sitting, but not when hitting bumps in the road. Hope you find this problem and it is an easy fix.


06-03-2012, 02:58 PM
I would also be looking at the genset fuses and fuse holders.

06-03-2012, 08:01 PM
saturday slid the genny out as i said and took the cover off the control box where the circuit breakers for the genny were. they seemed fine, but no way to tell. there was a wire bundle that the strain relief had come unscrewed so we fixed that but we didnt see any chaffed wired. the transfer switch i put in was a new one in a box that was in the bay of the bus when i bought it. it had never been installed and was an exact replacement for the one i took out.

it is simple. but hard.

1. wire between the genny and transfer switch (seems remote since it works fine when sitting still)
2. connections. i checked the junction box in the genny compartment and recrimped the smaller ones. i checked connections on the transfer switch
3. transfer switch itself. the transfer switch as a circuit board in it that detects over voltage, undervoltage, frequency variations etc and it will shut power off to the coach if there is aproblem for 50 seconds and then try it. when the power is shutting off when driving it is off for exactly 50 seconds then comes back on. so the power managment system in the transfer switch is either malfunctioning or detecting an issue.
4. the actual generator itself. the power head. not sure what to do to eliminate that. could the brushes be bad? how do you change them?

gotta get it figured out in the next month.

thanks, keep the ideas coming please.


06-03-2012, 10:26 PM
Tom, any way to test the output from the genset before the transfer switch?
Kinda sounds like you found the problem with the power cutting off for 50 seconds, just have to find what's causing it. If genset regulator is putting out high or low voltage or fluctuating frequency then the transfer switch is doing it's job.
Doesn't the genset blower get voltage directly from the genset? Might be able to check voltage/frequency there.
Good luck.

06-03-2012, 10:35 PM
the puzzling thing is why does it ONLY do it when i am driving and not when just sitting in the driveway running the genny.

btw, i have the surgeguard 40250 transfer switch/power monitor.


06-03-2012, 10:40 PM
Maybe pull the surgeguard board and reseat it?

06-04-2012, 02:19 AM
hi all,

this afternoon after church we unhooked the newell and darlene, our daughter heather and michael and georgia day went for a 30 minute drive. to see if we could discover anymore info about the generator cutting out.

it is hard to hear the genny running when driving but with several sets of eyes we were able to deduce the following that we didnt know before.

1. the voltage meters start dipping from 120v down to about 100v (both legs) and then the power management system cuts the power totally off like it is supposed to.

2. but we couldnt tell if the genny engine was dying down when it happened or not. so we kept driving around till it did it several more times and we were finally able to tell that the genny engine itself was briefly dying down at the same time. ahha....

3. now i know that it is actually and engine problem and not electrical, that makes me feel better. as richard says, it is either air or fuel.

now i am connecting in my mind another problem i had been ignoring. when the generator starts up, it starts up just fine and then runs for ten to 15 seconds then it coughs for 15-20 seconds and then starts up and runs fine.

so i am going to get a fuel solenoid and just to be sure a fuel pump.

i am running out of time and dont know if i have time to iterate.

thanks for everyones suggestions.

thanks to michael for watching meters while i was driving.

hope it fixes it.



06-05-2012, 10:15 PM
my fuel filter has a plastic screw on top, passenger side of the gen. Mine had a crack and so long as I sat still it ran forever.
As I drove, the screw rattled and sucked air....Gen died...this took mech. 3 hrs to find.....only by accident while setting a rag over the filter.
Cost about a buck to fix.....plus labor

06-06-2012, 01:06 AM
Can I be your mechanic??? I have a rag!!

06-09-2012, 03:23 AM
hi all,

i ordered an electric fuel pump from powertech. i installed it today and drove it for about a half an hour and it didnt cut out once. so that appears to have fixed it.

thanks to ever one for ideas


06-09-2012, 01:54 PM
Good on you Tom....another issue solved! Not missing your heat, but missing you and Darlene. You must be enjoying having Heather home!

06-10-2012, 07:13 AM
by the way, the pause on startup was cured by the new fuel pump as well. evidently it has a checkvalve built in it and it must have been not working and allowing fuel to drain back in the lines.