Can You Drive Without An Oil Pressure Switch?

Drive Without An Oil Pressure Switch

Note: As an amazon associate I may earn a small commission from qualifying purchases if you click to amazon from my site and choose to make a purchase.You can read my complete affiliate disclosure for more details

Can You Drive Without An Oil Pressure Switch?

Without an oil pressure switch, you will not know when your engine’s oil pressure wants. Therefore, your engine will experience a knock, seemingly from nowhere.

No! An oil pressure switch is typically used as an actuator that activates your vehicle’s oil warning light in the dashboard. The switch will indicate the presence of a safe oil level in your vehicle’s engine.

Why would you want to drive your car without an oil pressure switch?

If someone refers to an oil pressure switch, an oil pressure sensor, or an oil pressure sending unit, they’re probably referring to the same thing.

Usually, an oil pressure sending unit is an older part of an older vehicle. Modern-day vehicles don’t use oil pressure gauges to notify us of the oil condition but use an electronic readout.

However, if you have an oil gauge where a needle goes up and down on your dashboard, your vehicle uses an oil pressure sending unit.

While driving without an oil pressure switch is not recommended, it’s possible to enjoy your ride without it.

If you are not aware of what is wrong with your oil and your switch is sending the wrong warning, you can disconnect it or ignore it as you drive.

And you can drive for some time without any potential issues. The only problem will be that you won’t know when a problem crops up until it’s too late.

How Important Is An Oil Pressure Switch?

An oil pressure switch is typically used as an actuator that activates your vehicle’s oil warning light in the dashboard.

If the oil pressure in the engine falls below the critical level pre-determined by the manufacturer.

This part in your vehicle will bring a signal to the ECU in the event you have low oil pressure in the engine, preventing damage to your engine.

Engine oil is used to provide lubrication to mating and moving parts of an engine for reduction of friction, inhibiting corrosion, and cleaning.

To ensure that engine oil continues to perform its functions without fail, the engine oil pressure switch will indicate the presence of a safe oil level in your vehicle’s engine.

This is essential since if oil quantity by volume (oil level) gets below a preset threshold, it will negatively affect your engine.

A correctly functioning oil pressure switch is handy in keeping vital engine parts well-lubricated to ensure premature wear does not occur.

It’s also useful in the maintenance of ideal engine temperatures. If the engine experiences an absence of oil, severe damages will be costly to repair.

And you know the engine is one of the most expensive parts of your car to repair. Consequently, it becomes necessary to monitor your oil level.

But this will be a hard thing to accomplish without having the right device installed in your car.

To guarantee accurate results and easy monitoring, it’s needful to have a high-quality Oil Pressure Switch installed in your vehicle.

Does Oil Pressure Switch Affect Fuel Pump?

Yes, the oil pump gets a signal from the oil pressure switch to notify it when the pressure is low.

As earlier insinuated, a car’s oil pressure switch is meant to keep track of its oil pressure created by the oil pump.

This is an important thing as low oil pressure will easily damage a vehicle’s engine due to a lack of lubrication the engine greatly needs.

On older model cars, the oil pressure light receives signals from the oil pressure switch. This is a warning light that comes on when your vehicle is cranked.

However, the warning light goes off on pressure build-up. On the other hand, newer model cars have a signals that prevent your car from starting if it has low oil pressure.

But other vehicles have a gauge through which the oil typically ranges from 7 psi to 12 psi during idling and 40 psi to 60 psi when driving.

Is An Oil Pressure Switch The Same As An Oil Pressure Sensor?

No, but they perform the same function. While there is a distinct difference between an oil pressure switch and an oil pressure sensor.

They are largely confused by many, and the same name is used to refer to either of the two.

The general design of the oil pressure sensor happens to be a variable resistor sensor that increases and decreases resistance with changes in the oil pressure.

When oil pressure goes down, it reduces resistance but increases resistance when oil pressure goes up as the oil pressure goes up and down.

Technically, the oil pressure switch is either an open or a closed circuit.

A pressure switch is designed as a device that closes or opens a set of contacts when there are deviations of physical pressure.

But if your oil pressure sensor goes bad, the oil pressure light will come on.CLICK HERE to check current prices on Amazon Prime

Therefore, if you check your engine level and realize it’s okay, but the oil pressure light is on, you are staring at a bad oil pressure sensor.

If you wish to know the difference between an oil pressure switch and an oil pressure sensor, it might help first to appreciate the difference that is so obvious; the name.

Proceed to look at the different definitions I have given for the two and realize that these are two different devices.

Can You Bypass The Fuel Pump Relay?

Yes, it’s possible to bypass a failing pump relay, but it’s not necessarily prudent.

However, you can still bypass the fuel pump relay and get away with it if you are lucky enough and will not your vehicle this way all winter.

When you have a failing pump relay connected to your vehicle’s fuel system, your car’s competency to pump fuel will be compromised.

This will prevent your car from starting. Fortunately, you can easily bypass the relay and use your car.

Bypassing the fuel pump relay means diverting electrical power through an electrical skipper that directly connects the energy pump, denying the power relay.

You will need a skipper that will transfer current from the PCM to the energy pump. But your car should be on level ground before you start.

Now open the hood and identify the relay box, normally located on the right side of the battery, just behind the headlight.

Can I Mix 5W-20 Oil With 5W-30 Oil?

Open the cover from the box and look at the diagram on the cover to identify the fuel pump relay.

Remove the relay and use a flex wire to loop the “sockets” and see if it works. This should be pretty easy.

Can I Wire My Fuel Pump Straight To The Battery?

Yes, this should be a straightforward affair. But you need to be keen to ensure the wires go to the appropriate places.

You will need to remember that the fuel pump wiring is an important part of your vehicle. This is the device that delivers or pumps fuel to the engine.

If you screw up your fuel pump wiring, the pump will not work. And in this case, you know the car will not start as well.

There are two fuel pumps: those mounted under the car in front of the fuel tank and those that mount inside the vehicle’s fuel tank.

A fuel pump consists of the positive and negative (ground) electrical terminals, the relay switch for the pump, the fuel sending unit, and a fuse for use in the fuse box.

You want to start by paying attention to the electrical connections of the pump. The negative and positive wires of your fuel pump need to be labeled.

The positive should go to the positive of the car battery. Ensure that the wires have the appropriate length and all tight connections to avoid heating at the connection sites.

In addition to heating up, any loose connection might make your pump lack sufficient voltage to operate well, which can damage it.

How Do You Hardwire A Fuel Pump With A Relay?

First, identify the 12V wire from the ECU and cut it for a connection. This cutting ensures that one end of the cut wire goes to the ECU while the other goes to the fuel pump.

Proceed to connect pin 85 of the relay to the 12v supply wire from the ECU.  

When you connect pin 85 of the new relay to the 12v supply wire, your relay will be energized since the power goes there instead of going to the fuel pump.

Continue and wire pin 86 to the car’s body as the ground. You will need a wire from the battery to pin 30 on the relay.

Proceed to run a wire from pin 87 to the wire that runs to the fuel pump.

Again, as you install your pump with relay, remember that you are using DC, not AC.

Consequently, wire thickness is extremely important when it comes to the current it allows to pass through.

For instance, if you are using any larger pump of 320 LPH, you do not want to damage it by not powering it sufficiently.

This will not only shorten its lifespan but will potentially damage it. Therefore, avoid thin wires or even go for a direct wiring kit.

Does A Holley Red Fuel Pump Need A Relay?

Yes, Holley red fuel pump requires a relay. And it’s advisable to install this relay as you require your new pump.

Since Holley categorically states that they can’t be responsible for any damages from negligent connections and wiring.

It’s wise to ensure that the fuel pump manufacturer recommends your connections.

To mount the fuel pump, it’s best to mount it at the rear of your vehicle. Ensure that you mount the inlet and outlet of the pump below the lowest point of the tank.

If this is not done, you will be making it hard or impossible for the pump to suck the last drop of fuel out of the tank.

Additionally, ensure that the pump is gravity fed. But if it’s pulling from the tank’s top, it should develop a siphon feed to the pump.

Mount your fuel pump on the chassis vertically with its motor on top. Make sure that you don’t expose your installation to any moving parts.

Why Am I Not Getting Power To My Fuel Pump?

When you switch on the car, your pump should be powered (some of them will hum). But if you can’t get power to the pump and the relay, there is a problem.

First, you might want to confirm if the fuses serving the fuel pump, the main EFI, and ignition are not blown.

Any of these fuses will cut power to your fuel system. If all the mentioned fuses are cool, you might have a problem with the vehicle’s ignition circuit.

While not ruling out the possibility of a bad fuel pump relay, I would suggest a thorough investigation of the ignition circuit.

This circuit consists of the ignition switch and controls electricity to many components. These components include the fuel pump and relay.

Consequently, if it fails, you will not be getting any power to the fuel pump and relay.

Additionally, any circuit or switch problem will cut power to the fuel system, including a wiring problem. If the relay is bad, it will not allow power to get to the fuel pump.

This is because the two are connected in a series circuit, the relay preceding the fuel pump.

This means power first gets to the fuel pump relay before it proceeds to the fuel pump itself. With a bad relay, you can see that the pump will not get any power.

Does The ECM Control The Fuel Pump?

No, not exactly. But it does this by proxy. I mean this: your electric fuel pump uses a high current, so it can’t be controlled directly by the ECM.

However, the ECM controls a fuel pump relay connected to the fuel pump. After the ignition is turned on, the ECM briefly turns on the fuel pump’s relay before the starter engages.

If, in case within a brief moment, there are no ignition reference pulses received by the ECM, the fuel pump relay will be shut off until the engine is cranked.

As long as the relay circuit receives ignition reference pulses, the ECM grounds it.


You can drive without the oil pressure switch, but it’s not advisable.

Recent Posts