Hoping you guys can offer up some ideas: 2001 Bobcat 864 G Series (Triangle Headlights, if that makes a difference) The machine was running fine, when a main hose failed. During the repair, the cage was up for a couple weeks, while we were waiting on parts to arrive and doing some maintenance on the foot controls and such. We got the hoses made up, installed and when we go to fire up the machine, there is no voltage to the panel where the key switch is. The machine will fire off and run fine, when jumping the starter, so I know the battery is still capable. We have removed both the Left side gauge panel, as well as the key switch panel to check for corrosion or moisture in those. There was some, we dried it out, and noticed no corrosion or anything out of the ordinary. Still no lights or any indication of power to the key. We removed the key switch, tested it, and all was fine. I do have the service manual with wiring diagram, but it's limited in the sense that many of the wires show going in/out of the computer but don't indicate if they are supposed to be carrying voltage or not. In the fuse panel, we have tried swapping relay's around, no difference. When turning the key, I can hear one relay, moving, but none of the lights, or gauges move or any indication of any power going to the panel at all. Can anyone suggest a specific wire I should trace? Or a possible cause for this? We are out of troubleshooting ideas. Thanks!
Start at the key switch and find the wire which is always hot. If no wire is found on the switch which is hot then look for a fuse or breaker. If wire is hot. then turn the key to ON and find which wire just went hot and trace that wire.
most common place to look is going to be in the area of where the cab harness plugs into the main harness under the cab, ( most likely stuffed on top of the hyd tank near the filler hose). disconnect the harness at the LH panel find the red or red/white wire, & the black ground wire. that wire is hot with the key off check for batt voltage between the 2 wires, and also between the red wire and a GOOD chassis ground you're checking to make sure that a: you have voltage b: you have ground. if you have no voltage, go to the cab/mainframe harness connector, disconnect it, and start checking for unswitched power on the MAINFRAME side of the connector. that harness connector doesnt have the greatest seals in it to start with, sometimes the harnesses get twisted and pulled when the cab is raised and possibly broke off whats left of a wire. many times the insulation will show no obvious damage, but the wire strands can be broken inside... :drinkup
WOW, these are great reply's. Thanks so much for the advice.
Worked on a T300 once that did this. Took the mainframe/cab harness connector apart, didn't see anything obvious, no obvious damage/defect to wires coming to/from harness either, it was only when I probed the unswitched power wire on the mainframe side, good power, but then probed the same wire on the cab side of the connector, dead. Wire broken probably at the crimp inside the connector, jumper wire around it and all was well again. Welcome to HEF VinceHay. :drinkup
i hate that damn connector !! :bash i've run acoss a couple of the (newer) square, bolt together connectors with pins broken off in them both on track machines...... no idea *** happened. :drinkup
Yep, those of us who work on Bobcats with frequency, when there's an electrical problem, we're always suspicious of that thing by experience. :yup