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NH tracked skid steer strange safety & hyd solenoid malfunctions, LT185B

ylekyote

Well-Known Member
Joined
Feb 24, 2016
Messages
46
Location
CO
2006 year, 1600 hours, LT185.B New Holland. I'm second owner.

I was working on a pile of dirt and without warning or sign the boom lift stopped working and I was stuck with a load of dirt in it. All else works fine.

I removed the access panel and lifted the seat up.
Aux right hand control stick and Curl pedal are both moving in and out freely and work fine when machine is on and off. I think someone has improperly rigged / rewired the machine hydraulic controls to some extent, because shouldn't they lock when machine is off, and when seat belt is disconnected and seat is empty?

Boom lift (up & down) pedal is locked but all hardware / pedal appears fine.

All three plugs to the 3 solenoid do not have power at their plugs. Switched around the plugs, still no help or change. I don't have power on all 3 solenoid plugs. Seems like power interruption is before (as in closer to the battery) the 3 power wires separate to go to their respective solenoid plugs. Where does power for the solenoids come from? What places should I look to find interrupted / broken power? Or can a safety mechanism cause this?

I can't see the wire loom past 18" back (boom is stuck down so I can't remove side panels for better visual) and no diagrams I've found tell me either. I assume they may go to a different place than the Aux power wire goes, since they are separate wire looms? Or is it same place? Again, there is no power on all 3 of the solenoid plugs, even though the Curl and Aux solenoids seem to be working all the time, and never lock the pedal/stick, even with the loader off and key removed, seat belt off, and seat empty. I switched them around and nothing changed or improved. Made no difference so I put them back. So all 3 power wires to all 3 solenoids do not have power, yet only the vertical boom movement does not work. What is going on?

I connected a 12v jump start box to each solenoid to attempt to get them to actuate and nothing happened either. No sounds or anything. So I have no power to these 3 solenoid plugs, and no operation even if I apply power to the solenoid from a test battery.

All cab/motor compartment fuses seem to be good but I don't think any fuses relate to the hydraulic boom anyway. I checked 2 of 3 the engine compartment relays and swapped the two identical ones and nothing changed either. The third relay is twice the size of the other two and seem to be starter/ignition related because a heavy gauge red wire is connected to it, and a few others. Can the larger relay be responsible?

What and where could be interrupting the power to those solenoid plugs? Doesn't seem to be fuses or relays, unless it's the large one. Where does the power come from for the 3 solenoids? And what could interfere with the solenoids working when I supplied power from an external power source?

Would removing and inspecting the solenoids make a difference? I did not want to further disturb the solenoids until I get experienced inputs. I have pictures of all areas if anyone wants to see them. Thanks!
 
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