My 83' has been parked since April until now due to chasing a battery drain (was trunk switch) and then some body work. Converter worked fine before but now after 6 months of sitting in the elements it wont lockup. Its my winter rat so I dont want to dig too deep into it so is there any troubleshooting/diagnosing anyone can direct me to before the step of dropping the pan?

I quickly looked through the search threads and didnt find what I was looking for but forgive me if I was blind.

 

Well, the first thing to test is to see if the solenoid gets power when it should lock up. If it does, the solenoid valve in the trans has probably gone bad.