Re: Something wrong with my EF Falcon
upon reading the first part of your post, i thought...in order... loose tranny cable, Speedo unit, speed sensor.
Then you mentioned, the odd behaviour of the trannny.
Start by checking ALL terminals on your battery. This area is critical! every terminal and connection here has to be SPOTLESS!
I once had my tranny go into limp mode (locked in third) problem was simply a dirty terminal at the battery.
Failing this, it still sounds like an electrical fault...see an auto elec