Posted 1/11/2019 19:15 (#7238381 - in reply to #7237958) Subject: RE: Deere 8400 Park Break PSI switch Schematic
These switches are known to go bad. I have replaced several on 8000 series as well as 20 series. Sometimes they will work intermittently. Little tight to get in there but not bad to change. No calibration needed after changing. You can unplug and use jumper to check wiring under the particular pcu address. Can’t remeber which address is for park brake switch but could look up if you need. I would change switch. I think they are around $100.