Onan HDKAJ Temperature Sensor & Oil Pressure sender
I am posting this because I just had an issue with my temp sensor/sender on my generator and hard a tough time finding tech info or experience of others on the topic.
So, went on a trip and all was great. Was running the gen going down the road for the AC. Turned it off after a while. Next day went to turn it on again and it quit after 1 minute. I tried it again and after 1 minute it quit. Because it was shutting down each time after the same amount of time I suspected a sensor. I checked the code I was getting and it was pointing to over temperature. SO I checked my cooling system and all looked good. I was going to New England to FL and in August its pretty warm down south. Would have really liked to have known this trick while on the road.
Disconnect the wire going to the temp sensor and the generator will run. Of course only do this after confirming all systems are functioning properly. Had I known this I would not have 2 days of driving with 88 degree temps inside.
Any way, got a new sensor and went to put it in. Should be simple, unscrew the old one and screw in the new one. The old one broke off inside the housing. Not to fun! Had to dig out the broke piece and found corrosion build up all around it, that was locking it in place. After getting all the out I used a shop vac to suck out any debris that may have fallen into the housing. While doing this some antifreeze came out and ran down the side of the engine. No big deal right. Got the new sensor in and fired up the genset. It shut down right away. Not in 1 minute but after 20 seconds. Did this a couple times and keep giving me a first level code of 2 (low oil pressure). Checked the oil and its is fine. Looked for the oil pressure sensor and found about 10 inches directly under the temp sensor. So all that fluid that came out leaked onto it. I figured that the liquid may be causing it to ground out. Problem is I cannot get to that sensor with out removing the exhaust and inner bulk head. So I got back online looking for ideas, and I found a video from a generator sales place. They had been having issues with brand new generators shutting down as soon as their new clients turned them on. They figured out that if you unplug the sensor and then fire up the generator and let it warm, then while running plug the sensor back in, it should reset.
Since I could not get to the sensor I tracked the wire to a easy spot to get to and I cut it. I installed a bullet connector to the wire and fired up the genset without the wire connected. Ran great, I let it warm up and plugged the wire back in. Stayed running. I shut it down and let it cool. Then stuck my head in there to see the oil sensor and now I could see the fluid had dried all around it. Turned the generator back on and it ran fine.
So these 2 tricks about unplugging the sensors are a big deal to know about since the generator is made to be compact, the components are tough to get to, these tricks saved me a very large amount of labor and possibly more parts had I had to take of the exhaust. I have tried to title this post so that it will show up when others have the same issues.
So, went on a trip and all was great. Was running the gen going down the road for the AC. Turned it off after a while. Next day went to turn it on again and it quit after 1 minute. I tried it again and after 1 minute it quit. Because it was shutting down each time after the same amount of time I suspected a sensor. I checked the code I was getting and it was pointing to over temperature. SO I checked my cooling system and all looked good. I was going to New England to FL and in August its pretty warm down south. Would have really liked to have known this trick while on the road.
Disconnect the wire going to the temp sensor and the generator will run. Of course only do this after confirming all systems are functioning properly. Had I known this I would not have 2 days of driving with 88 degree temps inside.
Any way, got a new sensor and went to put it in. Should be simple, unscrew the old one and screw in the new one. The old one broke off inside the housing. Not to fun! Had to dig out the broke piece and found corrosion build up all around it, that was locking it in place. After getting all the out I used a shop vac to suck out any debris that may have fallen into the housing. While doing this some antifreeze came out and ran down the side of the engine. No big deal right. Got the new sensor in and fired up the genset. It shut down right away. Not in 1 minute but after 20 seconds. Did this a couple times and keep giving me a first level code of 2 (low oil pressure). Checked the oil and its is fine. Looked for the oil pressure sensor and found about 10 inches directly under the temp sensor. So all that fluid that came out leaked onto it. I figured that the liquid may be causing it to ground out. Problem is I cannot get to that sensor with out removing the exhaust and inner bulk head. So I got back online looking for ideas, and I found a video from a generator sales place. They had been having issues with brand new generators shutting down as soon as their new clients turned them on. They figured out that if you unplug the sensor and then fire up the generator and let it warm, then while running plug the sensor back in, it should reset.
Since I could not get to the sensor I tracked the wire to a easy spot to get to and I cut it. I installed a bullet connector to the wire and fired up the genset without the wire connected. Ran great, I let it warm up and plugged the wire back in. Stayed running. I shut it down and let it cool. Then stuck my head in there to see the oil sensor and now I could see the fluid had dried all around it. Turned the generator back on and it ran fine.
So these 2 tricks about unplugging the sensors are a big deal to know about since the generator is made to be compact, the components are tough to get to, these tricks saved me a very large amount of labor and possibly more parts had I had to take of the exhaust. I have tried to title this post so that it will show up when others have the same issues.
