Bobcat 335 Mini Excavator ignition problem No Start

[jsvidrine]

Bobcat 335 Excavator was running fine when parked. I have owned it for three years and is not used daily but is one of those great Kubota engines that always started immediately even with a weak battery. it sat for about three weeks after using it for 4 consecutive 3 hour days when I went to start it with ignition key and nothing, no clicks no lights on console, nothing. I even tried with the operator interlock (Left side operator console) in the down or closed position, no difference.

Trouble shooting included new battery; cleaned connectors, check all fuses nothing open, visual inspection of wiring harness; found nothing unusual with harness as far as i could see without tearing into machine. Opened the console and check wiring behind the panel; nothing obvious. Jumped hot wire from battery to starter and was able to get the starter to operate.

Checked voltage to the starter switch, found to have weak voltage (3vdc) on red wire after the three wire switch connector (where the switch assembly connects to harness) Decided to "hot wire" by shorting the red and green ignition wires, got lights on the console and an unreadable mixture of images for a code but nothing else. Added hot wire from the battery to the shorted red and green, engine turned over, started and ran as long as the hot from the battery was connected, remove that wire and the engine would die.

Is Ignition switch bad? Would like your advise before replacing bobcat replacement part is like $175

Thanks
Jv

 

[Billrog]

Only 2 things I can think of from my own experience with equipment starter relay or a fuse able link if there is such a thing still used.

 

[jsvidrine]

Only 2 things I can think of from my own experience with equipment starter relay or a fuse able link if there is such a thing still used.

Thanks for the reply

 

[SSdoxie]

The arm rest switch has no function regarding cranking/starting the engine. It only opens hydraulic flow to joysticks and foot pedals for hydraulic functions.
A red wire in the harness should read battery voltage when energized. Unplug the switch and check voltage of the wire that plugs into red wire of the switch. If that reads 12+v then contacts in the switch are suspect. If that wire reads low volts use a jumper wire to connect negative lead of voltmeter directly to battery ground and retest that wire. If voltage increases there is a poor ground connection, if no change there is weak connection in 12v circuit to the switch.

 

[jsvidrine]

Good direction, i will give it a chance as soon as the rains stops and festivities are done.

Thank you for the reply
Jv

 

[jsvidrine]

Update: found out i really did not need to "Hot wire" the green and red switch wires, only jump from + battery to red ignition switch wire.
So i performed the check recommended by SSdoxie and have 12.4 Volts on the battery, 9.7 volts on the red ignition switch wire which does not change if i check with ground to frame or ground to battery.

I have a wiring diagram and i am to start tracing wires and checking the relays, although i don't exactly know how to do that yet.

 

[SSdoxie]

Use the wire diagram to trace from switch wire back towards and check voltage at each side (incoming & out going) at any connections. Wires are color codes and number imprinted for easier tracing.

 

[jsvidrine]

Yes looks like the wire has an issue in the harness around where it goes under the hydraulics and the bend into the frame. I decided to make the cigarette lighter the new 5 amp ignition circuit, works like a charm. Thanks for the help