I have had this problem for sometime and the resolution then was for the TCC connector to be taken off the auto transmission. I believe it is still disconnected, but I do not remember where it is? Driver's side of the trans? I only suspect this because it has been in the shop for fuel and braks issues this past few weeks and it is possible some mechanic reconnected it.
However, now the fuse blows all the time when the car warms up. I know I need to attack the pink/black wire to all the different areas, but I would think the fact that it does not happen till the car warms up this would limit the places to check.
Any ideas?

New to the forum, so, Hello Everyone. :D

howdy! Welcome aboard!

Anytime a fuse blows when a component is connected correctly tells me there is a bigger problem that needs to be debugged.

OBDI engines use the info from the transmission so it knows what gear the tranny is in.

1987... there is a minor issue with the early (pre 1990) C4s... and most every car made prior to then, too... it's the fact that the SAE changed the requirements for wire composition. more accurately, wire insulation. Prior to that, heat, chemicals and time will cause the insulation to crack, chafe and pull away from connections.

I would debug the electrics... this is only the beginning.

Also, as mentioned above, there is a connector that reads info from sensors inside the gearbox. I wonder if you have some bad sensors....

to be honest, you need a Helm Manual - www.helminc.com.