This site may earn a commission from merchant affiliate
links, including eBay, Amazon, Skimlinks, and others.
This. The old incandescent bulb (1156) on the left has one contact on the bottom because it has one filament inside. The LED on the right is a replacement for an 1157 bulb that has two filaments inside (usually a marker/tail light AND a blinking signal light or turn signal light), and two contacts on the bottom of the bulb. If you look inside the receptacle in the light assembly into which you are attempting to plug these, you'll see either one or two corresponding contacts. They need to match. Look for the numbers on the base of the old bulb. They are usually stamped in there somewhere, or printed on the metal portion.the led looks like an 1157 bulb but the original one looks like an 1156. are you sure it’s the right bulb design. posts are off set on the 1157