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dharley · 08-05-2012, 05:29 PM

Well I just went to fire up the air conditioning on my motorhome and I have no power from the generator. The generator starts and runs just fine (its a onan marquis 5000) but no power to the coach. when I plugged in the shore power everything works fine. I have a switch in the back that looks like a regular house light switch that says shore power on top and generator on bottom so i am assuming that i have a manual transfer switch. With the shore power plugged in I have power to the coach whith the switch in any position even in the generator position. I dont have a multi meter at home right now so i cant check for voltage, but i have checked all circuit breakers and fuses and have found no problems. could my transfer switch be bad and stuck in the shore power position? the generator worked fine two weeks ago.Any help would be great, Thanks

nightriderrv · 08-05-2012, 08:41 PM

Check the breakers on the gennie to see if they are tripped, also the gen runs so it's putting out voltage it would not run if it did not output.

dharley · 08-05-2012, 09:04 PM

there are two circuit breakers and one fuse on generator, nothing was tripped and fuse is good

nightriderrv · 08-05-2012, 09:19 PM

I would get the meter then find the gennie wires and shore power make sure they are getting voltage to that point, then start with the switches. Is your unit a 30 amp or 50 amp from the looks of the switch don't look to be a 50 amp

smith45 · 08-05-2012, 09:28 PM

I have an Onan Marquis 6500 LP. It's doing the same thing. Starts and runs just fine but no juice. I checked a junction box where the wire from the genset ties in to wires going to the coach and --nothing there.. I called Onan-Cummings and they won't tell you anything over the phone, just tell you to bring it in. I can't afford their prices..

Chuck

dharley · 08-05-2012, 09:37 PM

Its a 30 amp.

nightriderrv · 08-05-2012, 09:40 PM

Did you check the wires at the gen to the box in the gen compartment or is that the box your talking about if there is no power there then the breakers could be tripped or bad it runs so it putting out volts

nightriderrv · 08-05-2012, 09:44 PM

OK then one feed will power to the switch the other feed should do the microwave alot were wired like that. take the switch apart check for volts on geni and shore lines then test the switch with a meter on continuity it looks like the switch is bad is change it out with the same style it needs to handle 30 amp loads

dharley · 08-05-2012, 10:24 PM

Ok I will test tomorrow. Does the switch look like an old style transfer switch?

nightriderrv · 08-06-2012, 05:31 AM

It looks like a light switch but it got to be some sort of two way switch, I have seen transfer switches but with a turn handle and a heavier looking part, but not to say there is not a switch looking like this that does the job

dharley · 08-06-2012, 05:54 PM

I got the multi meter out and was ready to start testing, so I fired up the generator and wouldnt you know it I HAVE POWER.

Everything works as it should today. the only thing i can think of is yesterday the batteries were kind of weak from sitting for about of week and the generator was slow to start yesterday. I plugged the coach in overnight and the generator started fast and worked as it should. Would a low set of batteries make a difference in this situation?

nightriderrv · 08-06-2012, 08:25 PM

Never seen that one, low battery's like you said Gennie spun slower but it started and being you have a manual switch you still loss power. 12V would not have anything to do with it. Only thing battery does is start the Gennie after it starts it's on it's own and supplies it's own power to run. so still do some trouble shooting could have Jared a wire and made it connect back again so just have a look through and still check the switch but it's good it's working, now we know it's something simple.

dharley · 08-07-2012, 05:08 PM

I'll keep looking into it, and i'll let you know if I find anything.
Thanks for all the help

Murf2u · 08-08-2012, 09:37 AM

Mine (MicroLite 4000) has done exactly what the OP said, started & ran fine, but with no output.

Yes, low house batteries will definitely cause the issue mentioned. The genny uses the 12 volt battery to excite the field coils which basically multiply the input power, 12 volts in, 120 volts out, 9 volts in, 90 volts out. If the batteries are low, the output is too, if it's below a certain threshold, it won't make power to safeguard burning stuff up.