My temp light is blinking on my '94 SSE.
Dealer wants to charge me $120 to tell me what the code means (OUCH!).

My preliminary tells me it might be the electric motor going bad on the actuator that controls the cold/hot air mixture that sits high up in the dash on passenger side.
Sometimes it will blow hot when set to cold and vice versa.
I've noticed that if I reach up and manually move the actuator with my hand that I can then get it to blow cold air.

Any opinions on what this might be?
Should I take a chance and replace the air mix actuator or should I shell out $120 to the dealership just so that they can plug there diagnostic tool in and tell me what it is?

The fact that you can manually move the airmix actuator indicates that it is hosed (gear is cracked). You've just saved yerself $120. Change the airmix actuator. Do you need a link to instructions on doing this?

Here it is anyway :
http://trialsnuts.com/ecc.pdf

Follow the Utards advice and you will be good to go. 99.99% sure the actuator needs to be replaced. Classic symptoms and the fact that you can manually move it and get cold air, is the kicker, like Stan said.