korte500 Report post Posted June 19, 2021 onan 7500 genset. randomly getting code 24 after 5 minutes of run time. it shuts off. get this... only when its warm outside. if i start it in the morning, its fine and runs for hours. currently 67 degrees and raining. same yesterday morning. if i try to start it later in the day when its 80 plus degrees outside. it will only run for 5 minutes, and quit. not looking forward to changing it out, as its in the front of my class A, pusher, and it must come out the bottom. Share this post Link to post Share on other sites
rayin Report post Posted June 19, 2021 (edited) I do not find an Onan code 24 in the. Onan Quietdiesel service manual, however #24 indicates a coolant sensor fault, the genset may or may not have to come out of the MH for replacement, it depends on your specific installation by the MH mfgr. IMO this can be simply a loose/corroded wire connection, or a complicated as a severely restricted cooling system, which will require out-of-MH repairs and cleaning. If the latter is actual, you might want to replace all coolant hoses, thermostat, and generator drive-belt while the genset is on the bench. When was the last coolant flush and replace? Edited June 19, 2021 by rayin Share this post Link to post Share on other sites
hermanmullins Report post Posted June 19, 2021 korte500, Welcome to the Forum. Listing of the make, model and year of RV would be a lot of help. Several things, Dirty Radiator, bad radiator cap, loose or no fan belt. Sounds like the sensor is doing it's job. Let us know what you find. Again, Welcome, Herman Share this post Link to post Share on other sites
wildebill308 Report post Posted June 20, 2021 Welcome to the forum. Bill Share this post Link to post Share on other sites
kaypsmith Report post Posted June 20, 2021 I once had a small leak in the generator radiator, it produced the same results. Could be as simple as the coolant is low. Share this post Link to post Share on other sites
korte500 Report post Posted June 20, 2021 the last 3 mornings it starts and runs for hours.. if i shut it off, it will not run for more than 5 minutes. 2004 coachmen elite 402ts diesel pusher. looks like i can lower the unit down and crawl in to replace the sensor. was just trying to learn a little. fresh oil and filter change. ive changed the coolant several times. it will not fail in the morning which seems odd. Share this post Link to post Share on other sites
fountaindavid.jean Report post Posted June 22, 2021 I experienced the same problem with my 7.5 QD. Crank, run for about 5 minutes and then shut down. I have the 02 Monaco with the front door which I had to remove and used a floor jack to ease the Ginny out. I had to remove the top and side panels to get to the sensor, so I replaced the fan belt, water pump and sensor at the same time hoping for a maintenance preventive. it's not a bad job, but takes a little time. Good luck with yours. David Share this post Link to post Share on other sites
korte500 Report post Posted June 24, 2021 On 6/22/2021 at 1:42 PM, fountaindavid.jean said: I experienced the same problem with my 7.5 QD. Crank, run for about 5 minutes and then shut down. I have the 02 Monaco with the front door which I had to remove and used a floor jack to ease the Ginny out. I had to remove the top and side panels to get to the sensor, so I replaced the fan belt, water pump and sensor at the same time hoping for a maintenance preventive. it's not a bad job, but takes a little time. Good luck with yours. David Thanks. mine runs fine the first time i run it.. but if i shut it off, and restart, it will only run for 5 minutes. Ill get to it next week. :) Share this post Link to post Share on other sites
