About a 1998 4wd4.3 (GMC) Jimmy. It has stopped shifting. The buttons to switch it into 2,4hi,4lo always blink between 2& 4hi I always hear something blinking in the dash on the passager side. WouldI

There is a safety switch on the brake peddle that prevents the car from going into gear unless the brake is depressed. If the switch becomes loose and doesn't engage the car will not shift. Until you can replace or secure the sending unite look under the shifter boot there is a plastic lever, (two actually that you will have to move out of their lock possission so the shift button wil push in and you can shift out of park. With the key off shift into N then start the car and it won't be a problem until you put it into park again then you have to go through the process all over again.

Oof