Hey there, in my 90 cherokee wont go off the break lock light! It starts going when i pass 5-10 mph, and wont go off till i switch off the engine. How can i figure out where the problem come from? Any kind of test i can do before i start to replace some parts? Cheers

 

If its an anti lock system, it might measure different wheel speed. Check all the tone wheels, maybee one of them is cracked. That could be it. It can also be a wheel speed sensor about to going bad.
You can measuure the resistance in them with an ohm meter. If one stands out, it might be that. Remember to check for shorts to ground in the sensors as well.

Good luck and let us know