OK I need some help from you JD Techs!!. Found the start problem with the 624G and it was the solenoid not disengaging from the Bendix. Now it or the other machine ( 544G ) will not engage the transmission. Called JD dealer and they said that it was the Ground speed sensor, so I got a new one with wires and replaced it. Still won't move. Next they said it could be the shift controller and I replaced it and still the same?. I swapped the computers and that did nothing. Parking brake will not disengage on the 624 but "WILL" on the 544G???. Can't seem to move either machine. Both will start, I can cycle the park brake control only on the 544G??.. What gives??? JD dealer say's they can't figure it out either??. I swapped the solenoids, and sensors from the working machine ( 544G ) to the 624G on the park brake manifold still no change. I don't have the schematics so it makes it hard to eliminate the key players. Any help would be most appreciated. Thanks Allan:beatsme
Have you checked the park brake relay? The park brake has to release before the trans will engage. Had a 644G that would not move first thing in the morning, especially if it was foggy. The door on the lower right side of the cab has a rubber plug for the a/c sight glass that was missing and moist air was able to get into the area around the relay panel. Replaced the plug, cleaned and sprayed the panel with silicone and it worked fine.
Yes it was one of the first thing at the fuse/relay panel I checked!!. I swapped it out with several other relays and still the same results. This machine has a gremlin somewhere in the electrical system. When you release the park brake you should feel the detent working below when you cycle the switch. I can't feel it on this machine, I can on the 544G though!!. This is what is leading me to believe that the problem is somehow related to the park brake circuit!!. I appreciate your response. Thanks Allan
Let JD dealer help you slove the problem completely.
How about the park brake switch itself? I just read through my 544G manual and nothing in the troubleshooting mentions that the park brake will not disengage. All I can think of is that the solenoid is stuck on the 624 and the service brakes are stuck on the 544. We had our service brakes dragging on our 544, the one pedal was stuck down. How about the F-N-R switch? Our 544 sometimes wouldn't shift into F or R and the F-N-R switch was bad. Good luck if you haven't already figured it out.
yes
flyboyziel56 Yes check you break switch .I have had them fail in the past .The contacts get carboned up .You can take the switch apart and clean the carbon off the contacts.Just take it apart slow and carefull. Also make up some test lead to raise the relay out of the fuse box so you can see if it getting the power when you need it .Sound like it is not closing .Making the circuit.The F N R switch should be the same for both machines also swapping them.