Sometimes its on sometimes its not it goes on randomly out of no where then shuts off this is an 1992 chevy s10 blazer 4x4 . any ideas why its doing that.

the brakes are fine

Also sometimes it stays on for a while then shuts off . I might go get it checked for codes =X

 

Could be one the the ****ty abs sensors On the wheel hubs. Man if i were you id convert it back to non abs style. Go to the junk yard and get the proportioning valve from a 85-90 s10 pickup. and all the front brake lines,Including the ones that run from the master cylinder to the valve and change it all out and be done with it. It;ll save you a TON of heartache with the old abs box's. I did this to my 92 2wd blazer.

 

would trow a code for me Chris ? and tell me witch ones malfunctioning

 

You dont need to go have the codes checked, you can do it yourself with the paperclip, just like getting engine codes. For engine codes you use the TOP 2 RIGHT HOLES and jump them with a paperclip then turn the key to ON with out starting it... For ABS I think you just jump the TOP LEFT MOST AND RIGHT MOST holes together, and turn the key on and watch the ABS light flash your codes.

 

For ABS brake system jump pin A to pin H. See pinout here and the ABS codes you will read.

ABS TROUBLE CODES - OBD1 & OBD1.5

 

If it comes on at 15mph on acceleration and goes out at 15mph on deceleration you have a bad brake light switch. Other than that check the codes (A - H).