If the other pickup being used is a humbucker check to see if it’s sealed or not. If it’s not sealed see if the magnet can be removed and flipped over 180 degrees. You may need to loosen the screws on the bottom of the pickup mounting plate to allow the magnet to slide freely in and out. If you can remove the magnet, gently slide it out and flip it over 180 degrees.

If not, try reversing the ground and hot wire in the pickup. Always try to reverse the wires at the main cable going to the controls. If you can’t reverse the magnet or hookup wire then you will have to find someone to remagnetize and calibrate one of the pickups.

Remagnetizing the pickup can alter the original sound and tone of your pickup. If you have a pickup you really like, don’t mess with it. Without proper magnetic calibrating equipment, having someone remagnetize your pickup can alter the sound of the pickup from how it was. The strength of a magnet can determine the output and brightness in a pickup, the polarity of the magnet can affect the phasing and remember if changes need to be made, make them to another pickup and not the one you like.