Where to start???? The vacuum switch on the brake is for the cruise
control.... it dumps the vacuum from the actuator under the hood. Having a
shift interlock that works in conjunction with the taillights wouldn't serve
much of a purpose... The interlock works in conjunction with the brake
lights and it is these that you need to check to see if they are working.

Forcing the shifter into reverse will only break parts unecessarily. Since
the default position for the shift interlock is "LOCKED", there isn't much
you can disable without digging into the steering column.... something I
would suggest you avoid until after you get a service manual and pre-read
any sections you need.

i have a 1992 Ford Aerostar 4.0 and i can`t get it out of park!! i can
put it into reverse by crawling under the van and pulling on the linkage
but not into drive... i have been told it may have a lock-out switch on
the brake pedal that locks it into park if your tail lights malfunction.
i checked my tail lights and they are working just fine....
there are two switches on the brake pedal one with wires and one
with a rubber hose.. i assume the switch with the rubber hose is the
lock-out switch... can i disable this switch so i can shift into drive
to move the van??...... or is the shift cable the culprit or possibly a
internal transmission problem??.........
PLEASE HELP!! i need to move this van ASAP

If the shift interlock isn't working right I believe you can work
around it.  Rather then starting the car and then fiddling with trying
to move the shifter, the first thing you do is put your foot on the
brake (to make sure the car doesn't roll) and just turn the key to the
first "click" which is the unlock position.  Then you should be able
to shift it out of park and INTO neutral BEFORE you turn the key any
further.  Once it's in neutral you can start it and once it's started
you should be able to shift it into any of the positions.

Check your fuses. I ran into this on my 2001 Explorer sport several years
ago. Factory trailer lightplug was causing it for some reason. Something
told me to check the cabin fuses and there it was. Sorry, but I can't
remember which fuse it was. Just pull them one by one and take a look.

-ron

i have a 1992 Ford Aerostar 4.0 and i can`t get it out of park!! i can
put it into reverse by crawling under the van and pulling on the linkage
but not into drive... i have been told it may have a lock-out switch on
the brake pedal that locks it into park if your tail lights malfunction.
i checked my tail lights and they are working just fine....
there are two switches on the brake pedal one with wires and one
with a rubber hose.. i assume the switch with the rubber hose is the
lock-out switch... can i disable this switch so i can shift into drive
to move the van??...... or is the shift cable the culprit or possibly a
internal transmission problem??.........
PLEASE HELP!! i need to move this van ASAP

Thank you for your help : )
after investigating i found the shift-cable was badly frayed and binding
the shift lever.. after removing the cable the transmission linkage
shifted smoothly and the column shift lever worked just fine...
(now my question is) when installing the new cable do i place the shift
lever and the transmission linkage into park and simply install the new
cable?... once again this is a 1992 ford 4.0 aerostar....
Thank you