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Bypassing the Onan/Cummins oil pressure switch can be done by just disconnecting the oil pressure switch wire, or you can change it.
Sometimes, bypassing your oil pressure switch is not advisable. Why? It’s not recommended by Cummins to bypass the switch, as it might cause a lot more damage in the future.
I’m sure you know that already—the damages it can cause. Although some reasons and circumstances warrant you to take this step,
Therefore, in this blog post, I will be sharing with you the location of the oil pressure switch, which situation warrants you to bypass the oil switch, things you should know before you bypass the switch, and how you can bypass it.
Let’s get started!
Is it advisable to bypass your Onan/Cummins oil pressure switch?
Then, you are prompted to troubleshoot the generator. First, you check the carburetor, which is fine, then proceed to the oil filter, which is also fine, and then the spark plug, which is fine.
To conclude, nothing is wrong with the generator, as the main reasons for the shutdown are not faulty, which might be the cause. I forgot to say that the engine crankcase is also filled with qualified engine oil.
But are you sure you’re using the right oil recommended for your Onan/Cummins generator?
I wouldn’t suggest anything on the type of oil to use because Onan generators are of different types and models, and each of them has their own recommended type of oil to be used.
And in the case of your generator shutting down, it might probably be a problem with the oil, which might lead to a faulty oil pressure switch.
However, if you’re using the right oil, you have nothing to worry about. It’s just a normal fault that’s supposed to happen to all generators.
But here’s the fact: in fixing this problem, you’re desperately in need of the engine. Will you wait till a professional comes by? I guess not; you can try something out yourself.
That’s where it’s advisable to bypass the oil pressure switch. However, if you do not need the generator as fast as possible, I will suggest you change the oil pressure switch instead; it won’t take long, and it’s probably not up to $50 if you’re to fix a new one.
Where is the Onan/Cummins oil pressure switch located?
As you can see from the image above, the Onan/Cummins oil pressure switch is located above the oil filter and beside where the spark plug is located.
Although, depending on your type of model, the oil pressure switch is generally located beside the oil filter with two to three 10 to 12mm screws holding it to the engine, which can be loosened up with a socket wrench set.
In this image, you can see a black wire connected to the pressure. The wire is the oil pressure switch wire that alerts the generator through its dashboard to the engine’s oil pressure.
Things You Should Know Before Bypassing the Switch
There are a few things you should know before bypassing your oil pressure switch. Firstly, you should know that when there’s limited oil in the generator, you won’t be alerted.
This is one of the main factors that makes it dangerous because, without being alarmed about the danger ahead, it might cause your generator to get damaged.
Secondly, the type of oil you use for your generator matters a lot. Generally, you should use SAE 10w30 synthetic oil for your generator.
Additionally, you should check your generator manual for the type of oil you can use. If you lost your manual, you can comment on the model below. Let’s look up the manual for you.
Lastly, after you have bypassed the generator oil pressure switch, ensure you always check the engine oil before starting the generator to avoid further damage caused by a lack of oil.
How to bypass the Onan oil pressure switch?
Bypassing the Onan/Cummins oil pressure switch is a very easy task you can do yourself without any professional assistance, except if you want to change the switch, which is still the same method you can employ.
Without further reading, let’s glance through the steps you can take to bypass your Onan/Cummins generator oil pressure switch.
✔ ️ Firstly, you get your plier, tape, and socket wrench set.
✔ ️ Secondly, locate the oil pressure switch, which I have shown you earlier. But depending on your generator model, it’s usually located by the side, below, or on top of the oil filter.
✔ Then remove the wire connected to the oil pressure switch with your pliers and tap it so it won’t be in contact with another part of the generator.
With this, you have bypassed your Onan/Cummins generator oil pressure switch. However, if you want to go further by changing the switch, you continue with the steps, which include:
✔ Purchasing a new oil pressure switch.
✔ Use the socket wrench set and loosen up the switch from the generator.
✔ Install the new one you purchased carefully, or better yet, seek professional assistance.
✔ Fix the wire you disconnected.
✔ And finally, start your generator and see how far it runs.
RECOMMENDED READ:- How to Remove an Onan Generator from an RV in 3 Simple Ways + Video
For RV owners, the Onan/Cummins generator shutting down when they need it the most is frustrating and tiring, especially when they are in a situation or location where they have no access to professionals.
So in this case, if the reason why your generator is shutting down is caused by the oil pressure switch, it’s recommended that you bypass the switch for the main time to allow your generator to run adequately.
But better still, after the whole process and now that you have access to a professional, you should change the switch and diagnose the generator to know what might cause it to transpire and avoid it in the future.