I would replace the BH relay. It’s a mother [censored] to replace because it’s in the lower left hand corner of the controller with all the traveler wiring in the way. Sometimes you can see burn marks on the face of the relay and sometimes the burn marks are on the back side that connects to the thin rail. I have had what I thought was drive problems bad brake switches a bad BP relay and I kept chasing my tail until I replaced BH. I have 9 of these GCS-R controllers on maintenance. If you Routine the controller and drive connections and use some canned air and clean them up good they are really not problematic. I hope this helps and good luck!
