Generator shutting down on high temperature

[T_Roy]

Yesterday while tailgating at a baseball game the generator on our 2015 Cornerstone started shutting down on high temp. At first I thought it might be load related because we had all 3 AC’s on plus the stove, 2 crock pots, and a rice cooker going. However after letting it cool down for an hour or so it would only run for about 1 hour before shutting down again. Prior to it starting this it had ran previously for half a day and a full night. We decided to just leave it off the rest of the day and come home after the game last night.

I started the generator when I left last night and it ran fine all of the way home including the 2 hours I wound up having to sit still in traffic due to traffic being stopped due to a wreck. So it ran fine for about 3.5 hours. Of course it was nighttime with cooler ambient temps.

I bought the Motorhome used in January of 2022 and I have never cleaned the generator’s radiator fins. I also have no clue if the previous owner did either.

I feel maybe that is what is needed is a generator radiator cleaning. Has anyone done this job and if so have any tips or tricks on the best way to get this done?

[RayandWendy]

I've just cleaned mine from the bottom with a brush and water hose. Also, check coolant reservoir level. Mine would overheat with low coolant even though it was still visible in the bottom of the bottle.

Later...
Ray

[d23haynes57]

For checking the coolant level you cannot always rely on the level in the recovery tank. You sometimes have to pull the small cover and take off the pressure cap and make sure that is full. The thermostat may be lazy or the over temp switch could be off. I would be nice if there was a gauge. Do you have any records of the coolant being serviced? Was there tall grass or anything that may have effected air flow? Did you try opening the gen slide out to get it out from under the coach. How many hours on it. Check the water pump belt.

[jacwjames]

Originally Posted by d23haynes57

How many hours on it. Check the water pump belt.

X2 on this.

[brobox]

If the pavement was hot and generator loaded, it will trip the heat sensor. If I stop at a rest area when it's hot to start the generator to run the roof air, my generator will also shut down until I start moving. Once on the road it will start and run fine. Nice the newer models will let you turn the AC's on from the dash, Classics, someone has to go to the back to the thermostat to turn them on after the generator runs for a couple of minutes. Do not turn the AC's on as soon as the generator is started, the generator needs a couple of minutes warm up time.

[DarkSideJeep]

Originally Posted by brobox

If the pavement was hot and generator loaded, it will trip the heat sensor. If I stop at a rest area when it's hot to start the generator to run the roof air, my generator will also shut down until I start moving. Once on the road it will start and run fine. Nice the newer models will let you turn the AC's on from the dash, Classics, someone has to go to the back to the thermostat to turn them on after the generator runs for a couple of minutes. Do not turn the AC's on as soon as the generator is started, the generator needs a couple of minutes warm up time.

Why not just set generator auto start on HVAC demand? I know on my coach the coach takes care of the start delay and will also only do the AC start ups one unit at a time.

[Poppedclams]

There is a thread back By chuck. I believe ray is correct. There is a radiator fins on the bottom of that year CS. CLEAN THOSE.. regular running that thing is best you can do. It's not going to hurt it fact is if you don't it's harmful. There is sensors that may gum up 1 being that heat sensor being a main issue from not using the beast.

[d23haynes57]

A few thoughts here. This is an 11-year-old rig. Minimal plans for generator maintenance. All is good as long as it runs. How many muti outlet adapters and extension cords? No indication of monitoring, volts, amps, load balancing for the 2 legs. Plug in heating stuff until it drops. And then comes the letdown. Possible equipment abuse. Response different if I was running my generator with a 30-amp load on both legs and it went out on high temp than I had a whole bunch of stuff on it and it overheated. Maybe it was at or just above the full load and then on the tri home that load was not there and it is all good.
I would wonder how the rest of the coach is maintained. There are lessons to be learned for folks looking to buy used rigs. These are the conditions that many coaches have endured.

The electrical equipment needs monitoring, and the operator should know how to use it for controlling and then when needed, diagnosing.

[brobox]

Originally Posted by DarkSideJeep

Why not just set generator auto start on HVAC demand? I know on my coach the coach takes care of the start delay and will also only do the AC start ups one unit at a time.

A lot of changes between 15's and 22's My 14 was not as sophisticated as my 21 so I gave information as it applied to my Classic 14.


Another factor that some don't think of if parked in dirt or sparse grass, it to put a mat under the generator so dirt is not constantly sucked unto the radiator and air filter.

[T_Roy]

Well regretfully I do not have any maintenance records so I do not know if the water pump belt has ever been changed. So I am going to put a plan together to get that done. I have changed the coolant and it has been serviced a couple of times since I bought the coach. Today, I cleaned the radiator fins from underneath. They were pretty dirty. After cleaning the radiator fins I fired her up and as of the time I am typing this she has been running for 11 hours with the coach parked and all 3 AC’s running.

I am going to add radiator cleaning to my regular service tasks.

[d23haynes57]

Originally Posted by T_Roy

Well regretfully I do not have any maintenance records so I do not know if the water pump belt has ever been changed. So I am going to put a plan together to get that done. I have changed the coolant and it has been serviced a couple of times since I bought the coach. Today, I cleaned the radiator fins from underneath. They were pretty dirty. After cleaning the radiator fins I fired her up and as of the time I am typing this she has been running for 11 hours with the coach parked and all 3 AC’s running.

I am going to add radiator cleaning to my regular service tasks.

For the belt how many hours? Probably 1,500hours would be a good time to service the belt and the water pump. It can be checked and if OK, leave it. For high hours and lack of use the other costly failure items are the brushes and the rear rotor bearing.
Engine coolant should be maintained. I use the same good stuff as you would for the engine. For oil these like synthetic and for winter the 5w-40 Diesel oils work best. I use the Mobil Delvac 1 or the Turbo Diesel truck formula. I also use the Mobil 1 204A oil filter. Just a bit larger for more capacity and a higher quality filter.

[rollyhomer62]

Older fuel lines get soft and collapse when hot
Replace fuel lines and remove any slack
Cummins Ocala finally figured this out on our 2015 Anthem (after 3 other Onan Dealers were stumped)
Routing of the Fuel filter lines, along with the lines to and from the tank were the problem areas