The following is based on a '98 S-10 wiring diagram:
If the new brake switch is adjusted properly you may have a problem inside
the multi-function turn signal switch.
You might be able to confirm this by pulling the STOP LP fuse and determine
if the brake lights still light. If they do the unwanted power is most
likely coming through the turn signal switch.
Motorsforum.com is a website by car enthusiasts for car enthusiasts. It is not affiliated with any of the car or spare part manufacturers or car dealers discussed here.
All logos and trade names are the property of their respective owners.