I just recovered my 1997 International 4700 rollback with Jerdan bed and now my hydraulics don't work. I don't know much about the hydraulic pump but I did notice that there is a connection at the back of the pump that was missing a wire. Does anyone know what the wire is for and what I should check next?
Do you have an under-hood PTO pump, that is electrically engaged? Or a transmission mounted pump?
The pump is transmission mounted.
Since your pump is trans mounted, it's likely engaged manually by a cable pull, therefore the wire is likely for an indicator light that lets you know when it's engaged.
Since the hydraulic system is fairly simple and all of your valves would not fail at once, it's most likely your pump or the gears that mesh the pump and trans that have failed.
You need to pressure test the pump, or perhaps drop it from the tranny and check out the gears. 
Thank you very much. When I pull the cable, it does engage the pump but nothing happens. I will pull the pump. Would it be obvious if the gears are the problem. Thanks.
HI allen410... Before you do that thou... check this. Is the cable slipping in the harness at the pump? Meaning... The cable could have come loose from the clamps during the "issue". Does the cable pull more freely than usual? IF it does then it could be either the clamp that holds the PTO cable housing or the clamp that holds the actual cable is loose. If this is so, then it could have slipped and is not engaging the PTO fully. There is one other thing. Try engaging the PTO with the truck off, then fire it up. Or... have some one fire up the truck, and try to engage the PTO by actual hand at the the pump. That will tell you if it is the pump gears going bad, and not a cable issue. this could /will tell about any of the affore mentioned ssues.Try these things first before you 'drop' the pump... Hope this helps!
Thanks. I did infact manually operate the pump lever. The cable was actually loose and I tightend the bolt. Once secure, the cable did operate the lever properly but still no hydraulic function. I will try the operation with the truck off.