As of 2015, MidwestHVACParts.com and RepairClinic.com sell wiring for furnaces. Both retailers sell furnace wiring that is compatible with many brands of gas and electric furnaces.
MidwestHVACParts.com sells wiring harnesses with connectors and attachments for brands including Carrier, Amana, Bryant, Goodman and Trane. The company sells main wiring harnesses as well as wiring made specifically for compressors. RepairClinic.com sells wiring harnesses for Carrier, Goodman, York and Lennox furnaces. The company also offers flame sensor wiring leads and spark, jumper, control board and electrode wiring. RepairClinic.com also sells terminals, terminal blocks and connectors that are necessary to complete wiring installations for furnaces.