F305330 Report post Posted November 6, 2015 I have a 2000 Monaco Diplomat. The generator cuts off when I run both AC units. There are times it will run a little while but usually after 5 minutes it will cut off. I can run one unit no problem, it is only when I turn the second one on. Have you heard of this issue before? I have had it checked out but they still can't locate the problem. Thanks, Steve Share this post Link to post Share on other sites
kaypsmith Report post Posted November 6, 2015 What is the size of the generator? Sounds like an overloading problem, if the generator is large enough to run this larger load, there may be an issue with the control board sensing capabilities. Share this post Link to post Share on other sites
rlbarkleyii Report post Posted November 7, 2015 Size of AC units and generator are both important, but we're both units OEM? If one were added there may not be a starting sensing device and when the second unit starts to run it will stall the generator if both start together. Share this post Link to post Share on other sites
blakeloke Report post Posted November 7, 2015 It could also be a fuel starving issue. Check to see if all of the fuel filters are in good order. Trace the line from the tank to the generator as there could be a filter on the chassis. Share this post Link to post Share on other sites
wolfe10 Report post Posted November 7, 2015 Steve, Welcome to the FMCA Forum. Please tell us what generator you have. When was the last time its fuel filter was changed (if it is a model that has a filter)? Share this post Link to post Share on other sites
tbutler Report post Posted November 7, 2015 The operation manual for the Onan generator has a list of error codes. When the generator shuts down, the light on the manual switch should be blinking. The number of blinks translates to a code that should tell you the reason the generator quit. Fuel starvation, low coolant, overheating, low oil pressure, etc. will all cause the generator to shut off to protect itself. Share this post Link to post Share on other sites
F305330 Report post Posted November 9, 2015 Thank you for the responses. I have a 7500 diesel onan. I have had it in the shop a couple of times but they can't seem to trace the problem. I just had the fuel filter and fuel pump replaced a month ago. Both AC's have been replaced as well. This issue is intermittent. There are times I run it and it will run 2hrs (while stationary). Then the next day when we headed out on our trip it would not run both airs. Share this post Link to post Share on other sites
aphotowizard Report post Posted November 9, 2015 My quiet Diesel 7500 runs two large A/C until full time in the desert so it should not be a sizing problem. Is it possible the problem is not with the A/C units, but with the position of the Coach. The fuel tank pickup on most units has a separate pickup for the generator. This pickup is set so that it can only draw about 3/4 of the tank before it come out of the fuel and the generator stops. This keeps the generator from burning all the fuel and leaving you stranded. I have had mine perform strangely when I was driving with less than 1/2 tank of fuel. Going up a grade the generator would stop. Running still and level it worked fine. Long accelerations the generator would stop. My solution was to keep more fuel in the tank. If this is your problem may need to adjust the pickup. Share this post Link to post Share on other sites
