753 skid steer bics backlighting stays on and no eng.crank

[darjamwag]

have a 753 bobcat,with out the deluxe ignition(have the key start style).Can run the machine and then when you shut it off and try to restart it the dash light on the BICS light up the hour meter and guages come alive,but the starter will not engage.When you shut the key off ,everything stays on.Pull the computer fuse,it will shut it down and resets.The machine will start,then shut it down and it happens again....Any suggestions????

 

[Dhandy]

sounds like you have aq sticky or bad relay that is not shuting down , also I would check the wiring and make sure there is not a drict short to power. put I would think the relay would more likely be the fix

 

[mrfixitpaul]

sounds like you have aq sticky or bad relay that is not shuting down , also I would check the wiring and make sure there is not a drict short to power. put I would think the relay would more likely be the fix

Possibly a bad key switch? When it is acting up, unplug the keyswitch connector and see if it stops or not.

 

[darjamwag]

Possibly a bad key switch? When it is acting up, unplug the keyswitch connector and see if it stops or not.

did all the usual,checking relays,fuses,etc.Disconnected the ign.switch,the rh control box,the lh control box(BICS),plug it all back in,and it is still all lit up,just like you left the key on.But as soon as you pull the fuse,its gone. I am finding that about the only time it acts up is eng.running,bar down,etc.Shut it off,and then it acts up.Checked for power at both control box plugs and have power at 2 wires,only 1 wire when computer is reset.Think I'm starting to suspect the main computer.

 

[Drhandy]

did all the usual,checking relays,fuses,etc.Disconnected the ign.switch,the rh control box,the lh control box(BICS),plug it all back in,and it is still all lit up,just like you left the key on.But as soon as you pull the fuse,its gone. I am finding that about the only time it acts up is eng.running,bar down,etc.Shut it off,and then it acts up.Checked for power at both control box plugs and have power at 2 wires,only 1 wire when computer is reset.Think I'm starting to suspect the main computer.

Have you ohm out the wiring. Did you check the relays for power wit the key off. I say that because you said you checked the relays I just don1t know how you did. Has the unit gotten wet may be there was water migration in to one of the plugs. Wish I had a diagram of the power distribution then I could tell you were to go to check it.

 

[Tazza]

Have you ohm out the wiring. Did you check the relays for power wit the key off. I say that because you said you checked the relays I just don1t know how you did. Has the unit gotten wet may be there was water migration in to one of the plugs. Wish I had a diagram of the power distribution then I could tell you were to go to check it.

If its only when the engine is running, what about the relay between the exciting wire for the alternator? Try removing it and starting it up and see if it goes away.
If the diode is bad, it will feed power back to the panel till the engine is off. Why its on the back light i have no idea....