A home equity loan can affect your score positively or negatively depending on how responsibly you use it. As with any loan, if you miss or make late payments, your credit score will drop. The amount by which it will drop depends on such factors as whether you've made late payments before. However, HELOCs are secured loans that are backed by your property, so they tend to affect your credit score less because they're treated more like a car loan or mortgage by credit-scoring algorithms.