Genny Overheats and Shuts Down, How To Fix

timmac wrote:

lucky13 wrote:
Ginnys have a high temp switch and a low oil switch.. sound like it is doing what it is supposed to do... These switchs go bad and sometimes need replaced.
Call your mfg and have them send you a new switch, does not cost too much and easy to replace, just screws it and plugs in.
good luck

Yea I might as well and upgrade those while I am at it, but when it does shuts down I go and check the genny and its very hot, even the door is to hot to touch, just not enough air circulation for our South West temps.

I have friends in Vegas and they said it's been consistently over 100 every day. Like 109 or some crazy temp. That's hot for an air cooled gen set sitting in a bin with no air flow, especially under a heavy load like AC's trying to keep up in an an RV.

lucky13 wrote:
Ginnys have a high temp switch and a low oil switch.. sound like it is doing what it is supposed to do... These switchs go bad and sometimes need replaced.
Call your mfg and have them send you a new switch, does not cost too much and easy to replace, just screws it and plugs in.
good luck

Yea I might as well and upgrade those while I am at it, but when it does shuts down I go and check the genny and its very hot, even the door is to hot to touch, just not enough air circulation for our South West temps.

Ivylog wrote:
Can you move a fan blade by hand? A old belt while tight will start to slip... you can buy a spray belt dressing that will stop the fan from slippy. I would try that first and if that fixes it... A new belt is in order.

This thread is about the generator over heating, not the motor.

Ginnys have a high temp switch and a low oil switch.. sound like it is doing what it is supposed to do... These switchs go bad and sometimes need replaced.
Call your mfg and have them send you a new switch, does not cost too much and easy to replace, just screws it and plugs in.
good luck

Can you move a fan blade by hand? A old belt while tight will start to slip... you can buy a spray belt dressing that will stop the fan from slippy. I would try that first and if that fixes it... A new belt is in order.

I installed vents similar to Joe b's. I used 2 white (you could paint to match), metal HVAC register covers and put them end to end. From a distance you can't even tell they are there. That was over a year ago and haven't had an overheat shutdown since.

Grill

I know mine is an old unit but the air cleaner intake can be rotated to either draw in warm air off of the exhaust manifold or twisted around away from the manifold to draw in cooler air.
Also how long does it take for the generator to cool down before it will run again?

Update on my genny issues.

Just got back from a long trip in Cali and did check my genny switch after it shut down and no codes, so I left the door open and my genny could run for hours without a issue, it seems it is overheating in temps around and above 94 degrees, however I cannot run genny while driving down the road to keep RV cool because it overheats, cant leave door open while driving.

So now down to work, installing a vent like the one in Joe B post and going to do something about the genny exhaust, reroute it and also install a cooling fan for the summer time.

"tinmac".....Where is yours located on the RV. Can you leave a door open, like the photo above and test to see if that resolves the issue. Is it in more of a compartment where you could add vents in the back of the compartment to allow the air to be drawn in better.

One of the 12 volt radiator fans used on cars would be a good addition and could run off your batteries (which are being charged). You could even use the thermostat on the fan to make it turn on and off as needed.

In reading on line there seemed to be a lot of conversations about the 5.5 KW Onan having over heating issues on some rigs.

We just acquired a new Fleetwood where they put the fresh air intake through the side of the compartment door. All the air being pulled in to cool the generator is being brought in directly from the outside away from the exhause and heat of the engine. Our Onan is a 4 KW single cylinder but something like this might work on the 5.5 KW as well.



Here is the vent from the inside with the compartment door open.



They added a removable flange with rubber seals to stop the intake of any heated air from the engine and exhaust system.