How to Test Guitar Pickups with a Multimeter

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As a guitar player, you are on the never-ending journey for a better tone. You often try different pedals, amps, and strings, among others. However, there’s one thing that you don’t mess with: the pickups. Because in the first place, they are quite intimidating.

The mere idea of tearing out the guts of your precious electric guitar could be stomach-turning even to the pros. 

A guitar pickup is normally made out of wiring, magnets and comes inside a plastic bag. Nonetheless, specific components might wear over time, including the casing, the plastic, and the wiring. 

What is a Guitar Pickup? How Are They Made? 

A guitar pickup is a set of magnets wrapped many times in insulated copper wire coils. That copper wire coil works by producing a magnetic field around the strings. It also produces a voltage every time strings vibrate. Then it travels through the gear and cables, leaving your amp as sound. 

Guitar manufacturers normally start the pickup construction process with a piece of plastic or fiberboard. The plastic is also referred to as flatwork, featuring six round holes punched out of it intended to hold pole pieces. They are cylindrical magnets that are ferrous metal cylinders along with a bar magnet underneath.

The magnets are carefully placed apart from one another at the same distance as the guitar strings. Generally, a magnet wire—that is insulated by a small layer of varnish—is wrapped around the magnetic structure many times. Smooth winds make the pickups sound darker, where a scatter wound coil produces a more crisp sound. 

The most typical types of guitar pickups are the single coils. Those are normally seen in the Fender Stratocaster. 

What Causes a Faulty Guitar Pickup? 

As you may know, the pickup is the heart of an electric guitar. Without that part, no one will hear those amazing sounds you’re playing. As stated earlier, the major types of guitar pickup are single coils, highly sought as the Fender guitars and humbuckers. 

Even though they are different, they follow the same principles and are assessed similarly. Pickup problems are normally a result of faulty soldering or wiring. However, guitar pickup coils could slowly break down. 

Here are the common signs you need to consider knowing if you have a faulty guitar pickup. 

  • Brittle solder joints and degraded insulation

Over time, solder joints are more likely to become weak and brittle. The wire that winds them could have a kink inside it that becomes compromised and worn out. Further, a wire could become detached somehow. 

The insulation inside the pickup could malfunction at some point, short the coils, and kill the output in the end. Damage to the insulation surrounding the wire could cause more issues, particularly when it comes to moisture. 

  • Exposed to humidity, water, and moisture

Do you live in a very humid region with at least sixty percent of humidity? Maybe your guitar is always in that environment. If yes, it’s highly possible that the coils, wires, and metals, among other parts, could be subject to deterioration. The guitar’s magnets could become corroded.

  • Exposed to powerful magnets

Please stay away from placing a powerful magnet directly in front of your guitar pickup, as it can strip some of the magnet’s power from it. This problem is extremely rare as most people don’t have a magnet strong enough to cause this kind of concern. But it’s better to be informed. 

How Do You Test Your Guitar Pickup?

When you are testing your faulty guitar pickups, a digital multimeter is necessary. 

Here are the steps you need to follow to test your guitar pickup properly and to identify whether it’s faulty or not.

  1. Access the guitar pickup to be tested. Keep in mind that it needs disconnecting the guitar strings and getting rid of the pickup guard on other models. Often, all the hardware is removable with a tiny Phillips head screwdriver.
  1. Disconnect the screws that surround the guitar pickup and eliminate any covers. The pickups’ inner workings and the two lead wires are now in view.
  1. Find the two pickup leads. You will find two wires connected to the pickup, which lead to electronics like the tone knobs and volume. One lead is positive, and the other lead is negative. These are typically coded by a positive red wire and black negative wire.  
  1. Prepare the pickup leads you to want to test. Grab your digital multimeter.
  1. To test the leads using a digital multimeter, the probes should contact the bare wire. Is the bare wire present at the end of the leads? Then, it’s not a problem anymore. But if not, the wire should be exposed. 
  1. Cut a small slit into every wire using a small knife or a razor. Make sure you cut just enough to plug the probes into every wire. 
  1. Test the leads with your multimeter. Set the range on the meter to 20K ohms. Are you using an analog multimeter? Then get a zero reading first by putting the two probes together and turn the Zero Ohm Adjust until your meter reads zero (0). 
  1. Measure the guitar pickup’s resistance. Insert the black probe to the negative lead and the red probe to the pickup’s positive lead. Your guitar pickup is in top working condition if you get a higher reading.

If you didn’t receive any reading at all, it means your pickup is faulty and needs to be replaced right away. Take note that single pickups must present a reading close to 10 ohms, and humbucking pickups must have a reading near 20 ohms. 

  1. Reassemble your guitar by covering the lead wires with electrical tape. Change any covers and attach the pickups again to your guitar.

Final Thoughts

There you have it! Just make sure your guitar is not plugged into an amplifier when you prepare the lead wires for testing. Also, you should always leave the wires intact and don’t ever try to cut across the wires.

We hope you find our post informative and engaging. The next time you encounter problems with your guitar pickup, feel free to visit this page again!

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