Aspects of this disclosure relate to a welding system that is configured to execute opposed, step, and parallel gap resistance spot welds (RSW) and associated methods. The system may be configured to switch bases to switch between an opposed weld configuration, a step weld configuration, and a parallel gap configuration. The system may include an accelerometer that is secured to the weld head adjacent one of the electrodes. The system may use the accelerometer to determine whether or not an RSW was defective. Acceleration data may indicate a defective weld when it includes acceleration data that is outside of a threshold range of acceptable acceleration data.