I have a 2004 XT90 Case Skidsteer - I bought a grapple and connected the hoses and tried to open and close it using the top rocker switch on my left hand control lever - no pressure. I was thinking it had to be either the rocker switch or the solenoid valve ??? Please help.
Why not attach a gage to a Quick Disconnect and check and see if you have any pressure. You could also put a tee in the pressure line with male QD attached before the valve and see if you have pressure. A gage is one of your best trouble shooting devices.
The wiring to the valve might be bad. With the grapple hooked up, unplug the leads on the valve and use a test lead from the battery to activate the solenoid. If the engine is not running, you may hear a click. If the engine is running, and the aux pump is working, and the grapple is plugged in, then the grapple should do something, open or close.
You should be aware if you deadhead a hydraulic line, you run the risk of damage. If the reliefs in the circuit are working, you might be OK, and you will hear it relieve.
Is the aux pump actually working? Is there a fuse inline anywhere. If you have a schematic, take a look and trace out the solenoid circuit.
On the aux Quick disconnects, on the front, do you have a male and female QD, or two of the same type QD.
If you have a male and a female QD, I believe the male QD is the pressure line.