Product review (5 stars): Furnace fixed in less than an hour!
The fan on our Trane furnace would not stop running even after turning off the heat completely.  After researching the problem online I found out that the fan relay switch was bad. I order the part and it worked perfectly.  We installed the part ourselves saving money not having to call HVAC repair company.  This relay is different than the original part it replaced.  Using the diagram included in the packaging,  each wire was marked as it was removed and then reinstalled in the correct position on the new relay.  Could not have been easier.  Take your time and it is an easy switch.