Crawl under the vehicle and check the U-Joint for any play. If there is even the slightest play in the joint it is defective. You can usually hear the joint when shifting from reverse to drive or visa versa.
Brake wear indicators are telling you that brake pads need replacement?Bad CV joint?Bad wheel bearing?
it could be a bad tie rod/a bad ball joint/a tire out of balance/ or it needs a front end allignment
A bad transmission.
May need to have the tires balanced, May be bad tie--rods, A bad u-joint can cause a bad shanking too. Belt could be brokin in a tire. Check these things first.
It is bad for fuel mileage.
Probably the fuel pump is bad.
bad clutch bearing
A bad engine temp sensor can do that.
Maybe a bad switch
Take the blazer to a local autozone to have the battery tested for FREE! but the blazer would not start if it sat for a couple days or so. also it would start hard, but once it started it would run fine.
Bad brake booster.
Bad sending unit in the fuel tank.