As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
HYD PRESSURE CAUTION LIGHT STAYS ILLUMINATED AND WARNING HORN IS ON WHEN THERE IS NO HYD FAILURE. NEW PRESSURE SWITCH PN MA124-01, SN 4021 INSTALLED. 185.4 HOURS LATTER IT FAILED, SAME PROBLEM, PN MA 124-01, SN 4136 WAS INSTALLED. 50.3 HOURS LATER IT HAD FAILED SAME PROBLEM. HAVE INSTALLED ANOTHER NEW SWITCH.