I see this is an old post. I just had a similar problem with the BICS system on my 873 locking up the brakes and hydraulics. My voltage was running high like yours. System voltage above 16 volts usually indicates a bad voltage regulator on the alternator. I swapped out my alternator and system voltage went down to a steady 14.5 volts. BICS is no longer locking everything up now that the system voltage is running in specification.

Hello I have a 763 highflow bobcat all gauges read good I lock down the bar and go and it locks up about like the park brake is on but its off I can 10 to 15 foot and bam it locks up if someone has a idea id sure try whatever thanks.