Dryer has no heat. Tested thermal fuse and heating element and they were both okay. High limit thermostat crumbled when I pulled off wires so I definitely need to replace it now; however, new part (279052) has three connectors and old part only had two. I've watched videos for fixing new dryers and there is a purple wire but my dryer is old and there is no purple wire. Do I have the correct replacement part? Do I just ignore this third connection? Thank you!