Hello, I am hoping some of the experts on here will be able to help me out with a problem. I do not have much experience working on bobcats but I do a lot of general electrical work and repairs. A friend contacted me requesting help with a bobcat that broke down in the middle of a job site. He told me that the sensor for the lap bar failed and the bobcat would run but the controls were all locked out preventing him from moving it. Before contacting me he attempted to bypass the sensor so he could move the machine out of the way. He tried to apply 12vdc from a jumper pack to the 3 wires the sensor plugs into After doing so the bobcat would no longer even start and the light for the lap bar blinks continually, even a new sensor he installed did not fix the problem. From my understanding the sensor is a hall effect sensor and those usually run off low voltage like 3v or 5v and the pin-out would be something like V+ Ground and a signal wire. Having 12vdc on any of those lines would be very bad and probably damage the circuitry that reads the sensors position. Would I be correct in assuming that he fried the electronics the sensor connects to? I tried to locate a wiring diagram that shows that sensor but could not find anything conclusive. Does anyone know what circuit board or controller the hall effect sensor is connected to or where those 3 blue wires go? Any help would be greatly appreciated.
seat bar works of sensor supply voltage that is 8V. sensor supply voltage also is available to charge pressure sensor eng oil pressure sensor coolant temp sensor seat bar RH aux paddle switch among other things by jumping the switch with 12 volts, it probably backfed to the main controller, most likely damaging it beyond repair. you are most likely looking at replacing the controller, and havig it reprogrammed by an authorized bobcat dealer... :drinkup
Wow, not to throw stones, but whatever posessed the poor guy to feed power into the system? :badidea
Thank you for your help crewchief888, so even with a new controller it will still have to be reprogrammed by a dealer? Also is the main controller the overhead panel with the lcd screen, or is it somewhere else on the machine? Im not sure why he decided to feed it 12v, I guess he thought it worked like a relay and he could some how activate it with external power. I wish he would have called me before doing that.
main controller is located behind the panel near the LH footpedal. before you start replacing components you may want to have a dealer hook up to the machine and see what else may be going on. they can retrieve any stored fault codes, and actually be able to diagnose the original problem. most dealers will not take a return on a controller, or any electrical component you buy it, it's yours, no refunds or exchanges. :drinkup
Agreed, even though it's going to cost you a few bucks, in this case, best have the dealer plug his computer into it. Sorry to hear about your trouble.
Sometimes in haste we make a wrong judgement call. I've been in this predicament a few times and have found that a little knowledge is worse than none. We forget that most everything you buy now has a "computer or main board" that controls numerous different safeties, the old school way of trouble shooting buy bypassing or applying power to different sensors and wires can cause more $$$ problems. Hope it turns out to be cheep fix, less than a 1K, I've had to pay thousands extra because a tech "thought he new", instead of a few hundred.