Why ar there exposed wires in there?

 

Yea, just moved in and notice it also, so I’m capping them off.

 

Why are the red and white wire connections exposed?

The other wires will be for the fan relay, common, and a cooling speed connection. Cap them and don't worry about them.

 

Thanks, they are already capped. So which wire is the fan, it’s usually green right?

 

Thanks, they are already capped. So which wire is the fan, itÂ’s usually green right?

Color doesn’t matter.
When in doubt trace them out!

 

Manufacturers make their own color choices. The wiring diagram will have that information.

 

Yes, however I cannot find a wiring diagram for my unit, and I've been searching for a while. This unit probably came installed when the house was built in the 80's.

 

Yes, that unit is very old, surprised it has not died yet. Best of my knowledge Trane never used Grey wires, and for some reason I don't believe the yellow one is yellow. I think they have discolored with time. Best not to touch them or you may end up without heat and a dead transformer.

 

i would call a pro and get that furnace inspected , have found many with cracked heat exchanger . the site bylaws do not allow the type of help you are asking for