Generator took out AC unit

Florida Guy · 07-03-2007, 06:20 AM

Running the generator (7.5 Onan Diesel) for the monthly exercise. Loaded the generator with the AC unit, about 22 amps. Five minutes into the run the generator speed increased and then shut down and of course the AC unit shut down also. Attempted to restart the Gen and it started for a second and then shutdown. The blinking light on the Gen. switch indicated a code 36. The manual says 'non operator shutdown.' Check fuel tank level and air cleaner. Fuel tank is full and the air cleaner is like new. Hooked up shore power and the AC unit will not start. The thermostat appears OK as I can hear a click as it usually does when things are normal. Checked the AC unit breakers and none tripped. I will be changing the Gen. Fuel filter to see if thats the problem, but I have no idea on the AC problem. Is there a thermal that needs to be reset? I always store the MH with full fuel and add an algea inhibitor to prevent condensation and algea buildup. If the fuel filter is not the problem then I'm lost. Any ideas will be appreciated.

Florida Guy · 07-03-2007, 06:20 AM

Running the generator (7.5 Onan Diesel) for the monthly exercise. Loaded the generator with the AC unit, about 22 amps. Five minutes into the run the generator speed increased and then shut down and of course the AC unit shut down also. Attempted to restart the Gen and it started for a second and then shutdown. The blinking light on the Gen. switch indicated a code 36. The manual says 'non operator shutdown.' Check fuel tank level and air cleaner. Fuel tank is full and the air cleaner is like new. Hooked up shore power and the AC unit will not start. The thermostat appears OK as I can hear a click as it usually does when things are normal. Checked the AC unit breakers and none tripped. I will be changing the Gen. Fuel filter to see if thats the problem, but I have no idea on the AC problem. Is there a thermal that needs to be reset? I always store the MH with full fuel and add an algea inhibitor to prevent condensation and algea buildup. If the fuel filter is not the problem then I'm lost. Any ideas will be appreciated.

Fakrwee · 07-03-2007, 06:44 AM

Hi Florida Guy, I had something similar happen to me. Generator conked out and wouldn't start. Checked fuses and reset and still wouldn't start. Took it to the dealer and they showed me a reset button on the generator that shuts down in case of a problem. Button is hidden behind the gen panel box. Yours may be different. hope this helps.
Tom

ISLAPP · 07-03-2007, 06:47 AM

As far as the A/C on shore power, there is a fuse behind the thermostat cover. Pull the cover off the front of the thermostat unit and there is a fuse there on the circuit board. Try that.
Mike

Route 66 · 07-03-2007, 07:00 AM

My 7.5 QD recently shut down with a code 12.

Inverter (within the QD) overvoltage.

My front AC wouldn't start on shore power either.

It tried to start but immediately shut down.

The AC had a burnt up start capacitor and a bad circuit board, which Newmar replaced under warranty.

Onan replaced the QD inverter under warranty.

I have the Progressive EMS, and I initially believed it failed to protect the AC, but after talking to the owner/designer of the EMS, he believes the AC failure was the result of the generator inverter putting out a really bad modified sine wave.

My EMS is working properly.

cbeierl · 07-03-2007, 03:06 PM

<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">... he believes the AC failure was the result of the generator inverter putting out a really bad modified sine wave... </div></BLOCKQUOTE>
That would certainly be odd, since the 7.5K Quiet Diesel has a pure sine wave inverter. Don't know what it was putting out when it failed, however.

Florida Guy · 07-04-2007, 08:21 AM

Thanks for the suggestions thus far. Checked the thermostat fuse and its OK. Have some out of town company so will have to wait a few days to change the fuel filter. A friend of mine changed his and said its a real Pain in the ...!

gunny · 07-05-2007, 12:12 AM

Your shut down of the generator was probably caused by a fuel filter issue, easiset and cheapest to try. Fuel filter change is easy, prime it when done and check for leaks.

As you have added an algaecide, you now have a good dose of weed killer in your fuel. Be careful if you get any diesel fuel on you and you will. Weed killer will be absorbed through your skin.

Watch your ammeter reading when trying to start the AC, if it goe high for a couple of seconds while trying to start and it not starting, very possible it is the start capacitor. Under $30 and also easy to change.

Florida Guy · 07-06-2007, 11:02 AM

Changed the fuel filter and generator still will not run. Discovered a burnt PC board on the AC unit. Dealer price for new board $275. Has two in stock so that tells me a somewhat common problem. Onan dealer said control board on the generator probably bad and most likely took out the AC PC board. Another $250 to fix the Generator. Have an appointment on Thurs. for the generator and will wait for the gen to be fixed before replacing the AC PC board. For those interested, will keep ya'll posted.

Route 66 · 07-06-2007, 11:48 AM

<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">That would certainly be odd, since the 7.5K Quiet Diesel has a pure sine wave inverter. Don't know what it was putting out when it failed, however. </div></BLOCKQUOTE>

Chris, you are of course, correct.

I should have worded that better, however we will never know what actually happened, but since the repairs, all has been working well.

Florida Guy · 07-18-2007, 07:58 AM

UPDATE:

Got the coach back with a new Generator Inverter installed. I replaced the AC circuit board so all is well (and VERY expensive). The Onan dealer had to remove the generator from the coach to replace the Inverter, as the Journey does not have a Gen. slideout. He said about 90% of the generators have to be removed to replace the inverter even with generator slideouts. Said most slideouts doen't come out far enough to remove the generator housing. The tech was very good, kept me informed and even took me out to the shop to explain things. He said he has replaced NUMEROUS inverters on the 7.5 kw diesel units and when they go, they usually burn out whatever equipment that was loaded on it. Guess it could have been worse, could have taken out the AC compressors also. As I was leaving he said, look at the bright side, I have never replaced a inverter twice on the same unit. Didn't make me feel any better though.