CAT 287B Aux Hydraulics - How do they work ?

[barnfab]

I have a 2006 CAT 287B which is missing the internals from teh Roller Switch so I am not sure if they work or not.

My question is that from what I can see there are two control valves that handle direction of flow. Now is it as simple as putting 12V onto one to get it to flow one way and 12V on the other to get it to flow the other ?

Or do I need to reverse polarity to make one close when I open the other ?

Any info on how they work would be appreciated so I can look to bypass and just use a push button switch.

 

[Nige]

I thought I sent you the electrical schematic for that machine..?
If I didn't post up a Serial Number and you're welcome to it.
IIRC the joystick controls send signals to the ECM which then signals to the valves.

 

[barnfab]

Serial Number is ZSA03469
Do u know if the ECM reverses polarity on the valves ? Or are they just single direction activation with a return spring meaning I power one for fwd and one for reverse ?

I think i saw a post u made with a bypass wiring to use the two buttons ?

 

[Drew77]

I have a 2006 287B and sounds like a similar issue. I roll the thumb switch forward and backward and hear/get nothing. Trying to use an auger and not going well. Any suggestions?

 

[Nige]

I have a 2006 287B and sounds like a similar issue. I roll the thumb switch forward and backward and hear/get nothing. Trying to use an auger and not going well. Any suggestions?

Serial Number.? I assume it's ZSAxxxxx but need to confirm.
Is this the first time you have tried to use an attachment that requires the thumbwheel switch.?
Did you move the Aux Hyd Switch into the appropriate position (Std or High Flow) before moving the thumbwheel.?

Is there an Operation & Maintenance Manual in the pocket behind the seat.? If not you really should get one.

 

[Drew77]

Hello Nige, yes the serial # is ZSA03585, and it is the first time connecting and trying to use an attachment. I did purchase the CAT O&M manual, and now wishing I had the service & maintenance manual as well. I did put 12V from a spare battery on one of the (2) solenoid valves just to hear it "click" with the engine off, but that's been pretty much it. Split and opened the joystick on the right hand side to see if there were any obvious pinched wires or issues, but did not see anything. Thinking of checking for voltage at the connector's ahead of the joystick to see if there is any voltage, but have yet to do so. Just hoping for some additional thoughts on easy items to rule out? Maybe verify the ECM's are okay? Help is greatly appreciated.

 

[Nige]

I'll send you the electrical schematic. You need to measure the "roller signal" voltage coming from the thumbwheel switch on P996 at CONN 33. Off hand I think the voltage should range from about 2.5v in the centre to 0.5v with the thumbwheel rolled all the way one way and 4.5v with it rolled all the way the other way.
Also check that the thumbwheel is getting the correct supply voltage. It should be 8V measured between P994 & P997.