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MACRacing · 07-11-2010, 11:29 AM

I have a long story on the generator and am in need of some help.

When I picked up the motor home it was cool enough the generator was running to run the heat pumps. We were there about an hour and it ran the entire time. We left and on the way home the generator shut off. It was on our way north and had since become dark and much colder (not sure if that had anything to do with it). It would start and run for a short time and then shut off again. Since then it has never ran correctly again. I now know how to check for the code it is setting a code 24. It is not sensing a temperature change in the first five min of running.

I decided to change the oil, oil filter, air and fuel filter and the coolant. I finished changing everything except the coolant and everything went fine but no change to the running and code situation. I then drained the coolant and went to refill. I noticed the coolant in the overflow did not drain. So I figured if it ran for a few min it would drain. Well it never did and for the first time the generator ran fine. It ran for 10 min, although I did not put it under load. No code and no problem. So I added coolant and went to run it, same problem again. It will start fine and run for 5 min, shut off with code 24.

So in summary it ran fine when I picked it up and seems to run better with out coolant than with.

Any thoughts would be appreciated.

Mat

Mike Canter · 07-11-2010, 12:52 PM

My guess is that the coolant temperature sensor is bad or the wire to it is disconnected.

Renipladlo · 07-11-2010, 02:22 PM

If you have the owners manual for the generator, there is a list of codes in the last part of it outlining what they mean or if you the end user can remedy. Based on what you said, it appears your genset is out of warranty. But you can call onan and they will tell you what the code means, and then you can go from there and decide if you want to tackle the repair or take is somplace. I don't have my manual handy otherwise I would tell you what it says. You can also download the manual, if you have the model and specification numbers which are on the dataplace of the genset. Hope this helps.

squeak · 07-11-2010, 02:26 PM

check the radiator on the underneath side mine picked up some debris and dot stuck in the fins

Mike Canter · 07-11-2010, 03:32 PM

Code 24 means that a coolant temperature change has not been detected on the temp sensor.

Dutch Star Don · 07-11-2010, 03:34 PM

Mat.....Code 24 appears to be an overheat code. When I changed my coolant, I had a difficult time getting it to refill. I tried running the generator hoping it would burp itself and let me fill it...it didn't. I panicked.....I thought I had screwed it up. I ended up pulling the top cover off. It was a pain, but not impossible. The screws on both sides of the gen are easy. The ones in the rear required me to sit on the ground, under the coach, with the gen slid forward. Once the cover was off, you have access to everything. I pulled the upper hose and thermostat and filled the engine directly through the thermostat opening.

You sound like you may have one or two things going on. Pulling that cover will allow you to check and make sure the fan belts are not broken, replace the thermostat if it's bad and open and fill the coolant directly through the top of the engine.

Others have very patiently filled the coolant by adding some to the tank and letting it sit, adding some and letting it sit. They are really a pain to refill.

MACRacing · 07-11-2010, 07:58 PM

Thanks for the replies,

A couple of things, I have downloaded the manual. Thats how I found out how to read codes. So I have known the code was for not reading a temperature change over the first 5 min. So I have been under the assumption it was a bad temp sensor or a bad wire. The problem is, if this were the case it would do it no matter if the generator had coolant or not, I would think.

After I posted I tried a few more things. I wanted to blow some air through the system to see if there might be a clog of some sort. I took the drain cap off and more coolant came out than I put back in. In all I drained about 3/4 gallon the first time and another 3/4 the second time. I had only refilled about half a gallon. (so when I thought it was empty earlier it was not) With the air compressor I blew into the fill hose at the top of the generator and air blew out the bottom end along with some more fluid although not a lot more. So now it should be empty of coolant. Just to see what would happen I ran the gen and in about 6 min it shut off with a code 33, overtemp. So I know the temp sender works and for the first time the coolant in the overflow tank drained into the generator.

Now I tried to fill the coolant and it took about a half of a gallon and the hose was full. So I ran the generator to see if it would flow and allow me to fill more. It never did, in fact I ran it for quite a while with one roof air on. No over temp and no code 24. I checked to see if I could add more coolant and it took about another 1/4 gallon. Part in the main fill and part in the overflow tank.

So maybe it was clogged or not flowing coolant correctly, although I am not sure if my problem is fixed. Why did it run on lower coolant levels now and earlier but not when full at first? Although according to the manual it only takes one gallon so I have it 3/4 full now.

Don, as far as removing the panel, the gen is not on a slider. I have taken the front cover off once in the beginning and it was not easy. I could not see the temp sender so I put it back on and have not taken it back off. I can hear the fan going and feel the air moving so it appears that is working.

I have also checked for debris in the front of the gen where the air intake is and didn't find anything

My next step will be to see if I can get the rest of the gallon in the system after it sits overnight. If I can and it still runs then I guess it is fixed.

Mat

bdpreece · 07-11-2010, 08:31 PM

You might want to change the thermostat. I'm pretty sure it has one.

MACRacing · 07-12-2010, 05:14 PM

Well today I was able to get the coolant full and run the gen. It ran for three hours with a air unit and the TV etc on. No issues. It didn't set a code 24 or over heat. I am still puzzled what happened and how it is now fixed but it appears to be.

I will watch it closely as I start to use it now.

Thanks again

Mat