7753 Aux Hydraulics

truckdiagnostics · Jul 6, 2015

My 7753 aux hydraulics will not work electrically in forward or reverse. I can hot wire them and get it to work. Has not worked since new and previous owner messed up the wiring. Below 19 is the control switch. It would be nice to know how that works schematically inside. The dealer wants $100 and they do not stock it. So, going there with the DVOM and figuring it out is not an option.

Below Number 4 is the control module. I can trace where power and ground go in from the battery. I can deduce what they are controlling going to the coil. However is the switch controlling a ground? So i am looking for a key to the wiring inside the magic box.

Here is the box on the loader, its a treat. Nice little potted module, with what appears to be a potted relay.

They wanted a $100 dollars for a switch don't want to think what the module would cost. So, if there is anybody that could shed some light onto the mystery on what is in that module would be greatly appreciated.
Please and thanks Steve

SSdoxie · Jul 9, 2015

At bottom of the Right side dash panel is the ON/OFF Auxiliary Mode Switch. With key on press on button once and upper green indicator light comes on. When the button is pressed ON 12v power goes back to control box to make connection and send 12v to the handle switch. The green indicator lamp grounds through the control box, and this ground tells control box which switches in handle to send power to. Press on ON/Off button second time and lower light lights up. If the indicator lamps are not coming on, the control box may be receiving 12v power but not getting indication of which circuits in handle to use.
With just upper indicator light on power to handle sends 12v to handle switch C, moving the paddle right or left sends power to the corresponding solenoid on the valve. Lower light on power also goes to the front trigger (detent) switch.