1991 chevy s10 pickup won't shift into park

if the a/t shift lever is locked up, park lockout is bad
or brake lamps dead or cars battery is dead.
we hare blind here can can not see what your hands are doing or even hear the engine run.

what transmission, here. automatic or manual stick shift?
S10 not blazer S10

old cars this old (pre digital documents) are hard to find and when found are not complete. or poor .
A/T box?
the PRNDL switch must be good. and cranks in both Park and neutral.
yes the relay clicks too, if not the PRNDL is prime bad part.
there is fuse named CRANK.(1st inline here)
the starter can be hot wired (a test) to prove starter work.
if stick shift TRANNY it is called the clutch switch. to crank,
some books say hood up fire wall, center is relay. IDK


see why we ASK transmission first/
if the relay does not click the fuse crank blown
or PRNDL is dead only on P mode, try N.
if stick shift,, clutch CCP switch bad or just mal-adjusted.
ST below goes to the relay then to starter solenoid
the relay colors are there. Green or Purple.

PRNDL is on side of TANNY part of shift linkage.

there is a possibility that it could cause numerous issues, including shifting and braking problems(w/ABS). The vehicle is doing adaptive strategy each time you reconnect and drive. Vehicles have to go thru 3 drive cycles, and this doesn't mean 3 trips to the store and back, to readjust after memory is lost from battery interruption.

There is a switch on the brake pedal that you must fix. This allows you to shift out of park only after the brake is applied.
Assuming since it goes in Park that its an automatic otherwise if its a shifter on the floor there is an actuator under the rubber around the shifter which if you lift it up yiou will find that you can manually move the piece which allows you to move the shifter.

ROCK THE CAR BACK AND FORTH.

Rock the car back and forth to remove parking pin from park .

If the vehicle will not shift out of park, a brake light switch or shift lock solenoid is most likely the problem.

Check your master and slave, If your slave is not fully depressing the pressure plate it would be very hard to shift.

Low fluid would not cause this. However there is a bolt on the side of the trans that you remove and put your finger in to check the level. If you put your pinky in and no fluid comes out it is low.

The slave often goes on the chevy's. It is internal, you have to pull the trans to replace it.

Also a pressure plate that is collapsing can cause the same problem. You are pushing all the way down, but it is not releasing.
Hope this helps.

loose selector rod or its worn & binding up
Check and adjust

Yes it screws in on right side of tramission and you will need a 7/8 inch deep socket to remove it. You may be able to clean the old one once it is removed. There is a little ball thatgets dirty and may you can get by with cleaning it. Good Luck. Ed