Today I was replacing the roof fan and a circuit breaker blew. I looked at it and it says "Furnace/ceiling fan" on the breaker that popped out. This makes me wonder if somehow the faulty ceiling vent/fan is causing the problem. We're replacing it with a different fan that doesn't have an automatic raise/lower switch so we have less wire to connect. I put the breaker back and got the fan working correctly but there are 2 loose purple wires in the picture below. Could these go to the furnace? Any ideas how to wire it?

It appears that the limit switch may be on the back of the furnace, which I'll have to pull out to get to.