Davit problem

[rourkeh]

Having problem with my davit.. It goes up when you turn switch to up, and it goes up when you turn switch to down. Davit does not have manufacturer name on it but looks like a older Marquip or similar. Hydraulic, manual rotation, no power extension, maybe 1000 - 1500 lbs. I opened up the control box on the side of the boom and there are 3 electrical connection switches 2 on one side 1 on the other.Otherwise all electrical and hydraulic lines run down the pole to aft deck box. Do not see a solenoid which was 1st guess.
Any ideas.

 

[Pascal]

The most common source of issues on hydraulic Davits is the remote. Open it up and check it. Most remotes don’t really secure the cable so any pull on the cable result in wires getting loose. Usually you ll loose the function of the wire that s loose but it could have moved and makes contact with another function. I always add a zip tie on the cable and attach it to the body of the remote to prevent relieve stress

 

[RonNP]

Check the rope or the cable. It may of overlapped itself causing your issue.

 

[rourkeh]

My davit is not equipped with a remote only up/down switch on outside of box on the crane itself.

 

[Pascal]

Hydraulic Davits usually have electric hydraulic valves to activate each function. They should be on the pump. Check that each get power when each function is activated at the switch.

I think that if you had a cable jam inside the boom you d hear it

 

[doc g]

Check that winding (coil) for the valve is connected properly , most of the time there are two coils on a valve that has reciprocal function. If they are not in the correct position you you can get issues like that . Also if the valve is stuck you can get this issue....Pat

 

[dottieshusband]

Hey, I'm not an expurt.. but dont assume it's an electrical issue. My John Deere has 3 function hydraulics. I've had a similar issue that was caused when a shuttle valve got stuck. Electrics throw a solenoid to move the valves.. when the valve sticks.. it does what it did before. The valve body has end caps that allow access to "tap" the valve. The less it gets used, the more it sticks.

 

[dottieshusband]

Yours will be different, but the black cylinder housings are the travel space for valve.. it gets stuck up or down.

 

[Pascal]

Some valves cane be manually activated by pushing on the tip

 

[doc g]

like I said " a stuck valve".....and some valves have two coils stacked on one side . I had one that moved down on the shaft just a bit and would not actuate the opposite motion. I held the remote to the way I wanted it to move and moved the coils and it worked. I later figured out someone had not put a washer /spacer in the correct position and both coils were out of alignment. I only figured it out by pulling apart another valve ! Basically what happens when you ask it move you are applying voltage to the coil which electro magnetically moves the valve inside.....hope this helps...…….Pat

 

[rourkeh]

Messed around with the wiring on the solenoids on the back of the up/down switch and got it working. Also hydraulic fluid reservoir was only half full of fluid so I topped that up as well. Must have a leak somewhere so I'll need to find that next. At least now I can get my dingy off the flybridge before this storm hits us in St Maarten on Wednesday. Thanks for the ideas and help
Cheers Rourke