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Bobcat 753C - No continuous flow

NCDiesel

New Member
Joined
Dec 23, 2018
Messages
4
Location
North Carolina
So I have had this bobcat for a few years - runs great!. Thumb paddle hydraulics work awesome and I've never had any issues even remotely related to hydraulics or hydraulic wiring. I will say I have always had a fault code on the BICS that is related - a single flash in loader valve light meaning "valve output circuit is open". But since all the hydraulics I've ever needed work well, I just ignored it

So I buy a log splitter for it and need continuous flow - first time I've even tried to use continuous flow. The trigger switch isn't activating it. A somewhat knowledgeable friend suggested changing out the right hand controller, being sure to buy the full package with new connectors. This helped in the fact it now triggers the interloc/brake if the seat bar is up but still no hydraulics.

Clues and facts:
  • Serial number 512724274 - mid 90s I'm told
  • Has "press to operate".
  • According to the manual, a machine with "Press to operate", should never have a single flash which is puzzling.
  • Has standard right hand controller - not "advanced", high flow, progressive or anything like that.
  • My procedure to activate continuous flow by double pressing the aux hydraulics button(i get both lights) and pressing the trigger switch. I have tried several other combinations (ie pressing thumb paddle first, parking brake set and unset, etc).
  • Log splitter operates fine if I hit the thumb switch and a friend operates the splitter
  • No seat sensor on this skid steer(think it may have been bypassed by a PO if you ask me because the mounting plate looks shop made).


So any ideas, information, tips, tricks etc you folks can pass along I would appreciate!

Thanks in advance!
 

NCDiesel

New Member
Joined
Dec 23, 2018
Messages
4
Location
North Carolina
Thanks crewchief888 - I did replace that - that's what I meant by the "controller" - I probably wasn't using the correct terminology. But that whole head "thing" on top of the right lever that has the thumb paddle and trigger was replaced.
 

crewchief888

Senior Member
Joined
Feb 1, 2012
Messages
1,781
Location
NWI
i believe your machine has an aux controller. it's (probably) located under the cab along the LH side of the mainframe, sorta near the LH steering handle base.


:eek:
 

NCDiesel

New Member
Joined
Dec 23, 2018
Messages
4
Location
North Carolina
So I have narrowed this down to something electrical. The thumb switch works in both directions and this activated each solenoid so they are good. I am now more interested in this controller under the operators seat on the left. Any ideas on how to test this?
 

Mike Lewis

New Member
Joined
Apr 14, 2021
Messages
4
Location
Tenn
753 C Question I have a BICS controller that will just loose power and lock the brakes and all hydraulics I have replaced the computer which is on the left side under seat behind left foot and wiring harness from the bics controller all the way to the bar replace all the fuses not sure we’re to go from here and my gut is getting sore from it locking down any thoughts or were to go from here? Weird thing is no blinking or anything all green light go out on the controller I should also add the only way to get it to power back up is to shut the machine down wait a second and start it up and it’s fine for a bit and it does seem to be something that happens after a while of running
 
Last edited:

crewchief888

Senior Member
Joined
Feb 1, 2012
Messages
1,781
Location
NWI
753 C Question I have a BICS controller that will just loose power and lock the brakes and all hydraulics I have replaced the computer which is on the left side under seat behind left foot and wiring harness from the bics controller all the way to the bar replace all the fuses not sure we’re to go from here and my gut is getting sore from it locking down any thoughts or were to go from here? Weird thing is no blinking or anything all green light go out on the controller I should also add the only way to get it to power back up is to shut the machine down wait a second and start it up and it’s fine for a bit and it does seem to be something that happens after a while of running

the BICS controller is behind your right elbow, the controller under the seat to the left is the aux controller. BICS controller gets it's power from the BICS fuse. clean the battery cables and battery posts, checks ALL the grounds then i'd start checking around the back side of the fuse block for corroded/broken wires.
 

Mike Lewis

New Member
Joined
Apr 14, 2021
Messages
4
Location
Tenn
Okay I will start there thanks so much any idea we’re I can get a wire schematic without purchase or is that the only way
 
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