How to Test 3 Wire Crank Sensors With Multimeters?

Crank sensors are used in many applications and can be found in most homes. They’re typically located on the side of an electrical panel or a gas meter, which is why they’re sometimes called “side cranks.”

When testing crank sensors with multimeters, there’s no need for any expensive test equipment to do so. All you’ll need is a few standard tools that most homeowners have already got at home, like a multimeter and some alligator clamps.

Testing 3 wire crank sensors with multimeters is pretty straightforward. The first step is to get the ground lead and one of the power leads on your multimeter attached to a suitable grounding point, like the metal part of an engine block, for instance. 

Next, you want to attach another power lead from your meter onto one coming out from the sensor’s wiring harness or terminal block – this will be either red or black if it’s a new style but could also be blue, green depending on what type that particular type was made as (and older varieties may not have any colored wires). Then touch alligator clips onto two remaining terminals, which are left unconnected, and then start measuring!

Testing Methods of Multimeter 

If you suspect your car has a bad crankshaft position sensor, there are few ways to test it. One way is by using an automotive multimeter which can measure voltage and resistance. 

To do this, remove the sensor from the engine bay and then attach one end of the multimeter to each wiring lead coming off of it with alligator clips. If its resistance reads zero (or infinite), that means it’s shorted or open, respectively- therefore telling us that we may need new parts for our vehicle!

Here is an easy way to test out the crankshaft sensor. Hold your multimeter’s probes onto either end of a wire that connects two connectors, and set it to AC millivolts. With someone else turning on the engine and you watching for fluctuations in voltage output, make sure they are not touching anything around the car as well! 

Suppose there are no changes when probing with one probe while rotating them back-and-forth between both ends of these wires. In that case, this means something needs adjusting or replacing – take off all clothing from any parts near moving gears before getting close enough, so you don’t get cut by metal pieces flying at high speeds!

So, how do you know if your crankshaft position sensor needs to be replaced? Well, for starters, it’s a good idea to make sure that the battery is charged and properly connected. If there are still no results, then proceed with our tests down below!

Let’s test this out first before we jump into replacing anything expensive. When starting up the car, make sure that there isn’t an output tone of 200 millivolts from your vehicle’s computer system while running in the park or neutral gear at 1500 pm on a digital voltmeter; otherwise, feel free to replace it as needed!

Checking if Camshaft Sensor is Bad

The camshaft position sensor can go bad over time, but you’ll know if it’s needed to be replaced because of the following signals.

The vehicle stops repeatedly.

The engine may accelerate slowly, or the fuel consumption is inadequate. A camshaft position sensor should be replaced if your car has either of these drawbacks. 

Other problems could also cause similar symptoms to this, so it’s essential to pay close attention!

The check engine indicator is on.

As soon as the camshaft position sensor has specific faults, a light on this indicator will come on. 

However, here you should note that the light of this indicator can also be triggered by other reasons such as aging or dirty car engine parts. That’s why it’s best to take your vehicle in for an expert diagnostic scan and find out what fault is causing these lights!

The vehicle won’t start.

If you have had any of these problems, then your car is close to not starting. The camshaft position sensor can deteriorate, and that will cause other parts of the vehicle to break down as well. This situation is terrible because it could happen when you’re driving or if your car’s parked, so be sure and get everything fixed!

Testing a 3- Wire Sensor

  1. The ground wire should be found near the battery, with power and signal wires following from that. You will need to test your multimeter’s voltage setting after identifying this location to check out the sensor’s circuit correctly.
  2. Turn the ignition key on and let the engine stay off.
  3. To test the wiring of power, touch your multimeter’s black cable to the ground and its other probe wire on a nearby (labeled) red or a white-colored power wire.
  4. The readings on the multimeter should be checked to make sure they are by what is specified in the manual.
  5. Let your helper start your car’s engine.
  6. Ensure to touch the ground wire with your black cable and the signal wire with your red probe.
  7. You should check your reading and compare them with the specifications of your car’s manual.
  8. If the voltage reading is lower than your car’s specifications, or if you’re not getting any signal from it at all, then there are high chances that the sensor has failed.
  9. If the sensor is still not functioning, it may have been damaged physically. Uninstall and diagnose for symptoms of physical damage such as corrosion or broken wires.

What are the symptoms of a faulty CMP? These signs include intermittent rough running, hesitation, bucking, unstable idle—prolonged crank time on cold engine; stalling or stumbling when accelerating, and lousy fuel budget.

Resetting a Crankshaft Position Sensor

An effective way to do this is to disconnect the battery. After that, you should keep it disconnected for an hour then reconnect it after a full charge of at least ten minutes with no electrical load on your engine. 

This will allow you to reset the light and eliminate any memory glitches to have a car running without interference from other parts like headlights or radios!

Changing Crankshaft Sensor

There are a lot of inconveniences that you may encounter when replacing your crank sensor. 

This process is essential if the car doesn’t start up or runs poorly, so don’t let this test drive off in frustration! One thing to keep an eye out for during installation includes the long stem, which can get stuck inside and make things difficult. 

When removing the old crankshaft sensor from its spot on top of the motor block, be sure to hold onto it tightly with one hand while rotating and pulling it out towards yourself – never twist back toward the engine mount/block as pieces will break off quickly once they become loose enough. 

Once removed, there should be plenty more room around where the new part goes now; push into place starting at a base near the transmission.

A malfunction of the crankshaft sensor could result in a lot of problems for your vehicle. A multimeter is essential to test this component’s performance so that you will be avoiding those future repairs and costs!

The best way to avoid many problems and failures in the future is by investing in testing your crankshaft sensor. It could be beneficial because it’s one less thing that you have to worry about when driving around town or visiting family for Thanksgiving this year!

About Blake Sutton

Blake has worked as an electrician for over 10 years, receiving his Journeyman Electrician license in 1998. Looking to take his professional electrical career further, in 2008 he received his Bachelor of Science in Electrical Engineering (BSEE) from the University of Texas in Austin. Blake now works full time as an electrical engineer, specializing in power systems.