bobcat 763 2002 model will not turn off

[tnsparky]

This is a intermittent problem. When it will not shut off I just pull the power on the fuel shut off solenoid on the motor. I took apart the panel in the cab took a look at the switch, cleaned and blew out the fuse panel with air and did not have a problem for about a year but the problem has started again. Someone told me there was a timer but they were not sure where it was on this machine, tried to contact local dealer but they are as useful as tits on a boar hog.

 

[Tazza]

That seems weird....
There is a timer, but the timer is for the pull coil only. It runs for a few seconds at startup then turns off. The key should supply power to the hold coil that keeps the shut off lever in position till power is lost. Could it even be a stick contact in a relay?
You may need to probe the power back to the switch and se what its doing. Have the key on then pull the lever back, it should lock into place unless the speed sensor detects its not running and turns off.... Turn the key off and see if the solenoid holds there, if so, probe it back and see where the power is coming from. It should be connected to switched power, so key off = solenoid power is off too.
I'm sure its something simple, just weird as the problem is usually reversed, it will start then die as no power is at the hold coil.

 

[tnsparky]

That seems weird....
There is a timer, but the timer is for the pull coil only. It runs for a few seconds at startup then turns off. The key should supply power to the hold coil that keeps the shut off lever in position till power is lost. Could it even be a stick contact in a relay?
You may need to probe the power back to the switch and se what its doing. Have the key on then pull the lever back, it should lock into place unless the speed sensor detects its not running and turns off.... Turn the key off and see if the solenoid holds there, if so, probe it back and see where the power is coming from. It should be connected to switched power, so key off = solenoid power is off too.
I'm sure its something simple, just weird as the problem is usually reversed, it will start then die as no power is at the hold coil.

Hi Tazza, It seems to be coming from the hold coil, back probed the hold and pull turned key off and when the problem came up I tested both and only hold still had power with key in off position. Tried to apply power to just the hold wire with bat disconnected and trace the wire but hard to do without destroying the harness because just testing in the fuse panel showed power in many different places. Do you know where i can get a wire diagram? I asked dealer here in Nashville but it was like I was asking for his first born.

 

[skidsteer.ca]

Hi Tazza, It seems to be coming from the hold coil, back probed the hold and pull turned key off and when the problem came up I tested both and only hold still had power with key in off position. Tried to apply power to just the hold wire with bat disconnected and trace the wire but hard to do without destroying the harness because just testing in the fuse panel showed power in many different places. Do you know where i can get a wire diagram? I asked dealer here in Nashville but it was like I was asking for his first born.

I put a GM alternator in place of the Mondo on a 853 and it did this. It was backfeeding current into one of the small wires thus keeping the power wire from the key to the fuel shutoff energized. I wonder if there is a diode in yours thats gone bad or if someone swapped the alternator like I did.
You could try unhooking the small wires on the alternator to see if that helps with it shutting off.
Ken

 

[tnsparky]

I put a GM alternator in place of the Mondo on a 853 and it did this. It was backfeeding current into one of the small wires thus keeping the power wire from the key to the fuel shutoff energized. I wonder if there is a diode in yours thats gone bad or if someone swapped the alternator like I did.
You could try unhooking the small wires on the alternator to see if that helps with it shutting off.
Ken

I will take a look, I believe it's the original alternator machine has only 1200hrs. I beginning to think it might have something to do with the computer. I pulled all the relays& fuses when the key was off and machine still running and nothing cut it off but the computer fuse. I unplugged the connectors going to the controls in cab and that did not shut it off. I pulled on the wire harness thinking might be a bad wire or something but no luck. I did disconnect the two computer plugs and cleaned some of the dielectric grease off and reconnected and the machine started shutting down when you would turn key off but not a lot of time to try it so going to run it some more today.