I have an older Goodman furnace that is doing something similar to a short cycle but I would consider it running out of order. What's happening is that the furnace kicks on when the temp is called for by the thermostat. You can hear the combustion motor running first then you can hear the ignitor click and see it ignite just fine. However the blower doesn't kick on... What happens then is that the limit switch kicks the burners off due to high temp THEN the blower kicks on. The blower continues to run until the limit switch kicks off and then allows the ignitor and flame sequence to recycle and then we get heat. I've played around with it by leaving the fan turned on (at the thermostat) and get a similar result.... Fan runs constantly until thermostat calls for heat. Fan kicks off. Combustion motor begins to run... Flame ignites... Limit kicks then fan begins to run. Limit kicks off then furnace ignites and blows warm air. Any ideas as to why my blower isn't running for the initial flame cycle?

There's a lone blue wire upstairs where the thermostat is that is unused; the other four wires are used. Downstairs, at the furnace, there are three blue wires. [URL="http://imgur.com/wSsN12o"]I've labeled 'em for you[/URL]. I have no idea which blue wire is the wire that's going upstairs. I'm assuming it is wire 1, because the insulated bundle of wires that wire 1 is in are all going to terminals, so that makes me think those are all the wires going upstairs to the thermostat. It could be wire 2, but for some reason I feel like it's not because it appears there are three unused wires in that bundle. I dont think its wire 3 since that one goes into a wire nut, but I don't know. I just can't make heads or tails of this. Is there any possible way to figure out which wire is the one I need to connect to the C terminal? [URL="https://imgur.com/a/KJPpT"]Here are a bunch of other assorted pics of the furnace in case it helps[/URL]. THANK YOU SO MUCH!