Bobcat 763C BICS won't turn off

[Shifted_04]

Serial #: 512217583

With key removed from machine, power to the BICS unit and hydraulic pressure warning light are constant. Thinking it might be the key switch I disconnected the wires on the back of it with no change. If I remove the keyed power relay then power goes out (not a relay issue - already swap-tronics to one of the other relays). I unfortunately don't have a wiring diagram so I cant tell if the power or ground side of the keyed power relay is switched.

Also noticed the fuel shutoff solenoid is hot. Assuming the pull in windings are staying energized. 12V present between red and black fuel shutoff solenoid wires with key removed from switch.

No wiring hackery present.

Automotive repair instructor by trade. First Bobcat I've worked on. Feel blind with out wiring diagram.

Any help/guidance would be greatly appreciated.

 

[foton]

I would go to the fuse / relay panel and pull out relays and fuses one at a time till the display goes off. that away you will then know what circuit it is on. get wiring diagram an go from there. good luck

 

[Shifted_04]

I would go to the fuse / relay panel and pull out relays and fuses one at a time till the display goes off. that away you will then know what circuit it is on. get wiring diagram an go from there. good luck

Appreciate the quick response. Already did that. I believe the issue is in the control side of the Switched Power Relay. To my knowledge with power or ground on the control side of the that relay should be controlled by the keyed switch. Keyed switch has no effect on voltage across the control side of the circuit. Even if the keyed switch is completely disconnected so believe I may have a short or back feed someplace. Have read of issues with diod failure in alternator allowing to back feed circuits.

 

[Shifted_04]

Unplugged the alternator and constant power to the control side of the keyed power relay went away. Every picture I've seen on Bobcat's Mando alternator has the red wire on the S terminal and the Purple wire in the Exc terminal.

 

[foton]

I wonder in the past the alt. was not charging and they put the hot on the exc post which I assume is the sense wire post? I have heard of this on 6 volt generator gas tractors converted to a automotive 12 volt one wire delco that you would have to rev. a bunch to get them start charging.

 

[Shifted_04]

I wonder in the past the alt. was not charging and they put the hot on the exc post which I assume is the sense wire post? I have heard of this on 6 volt generator gas tractors converted to a automotive 12 volt one wire delco that you would have to rev. a bunch to get them start charging.

Not sure why they have both on the Exc (terminal R) post. The red wire is definitely suppose to be on the terminal S post and the purple on the Exc terminal R post.

The Exc terminal R post should only put out 1.3-2.5V so not sure why they would have both connected to that.

Believe terminal S should have battery voltage.

Hopefully going to test after work and see what I have with the wires on the correct terminals.

 

[foton]

I agree, if what was done to keep it charging all the time ,wires should have been on S