I have a shop manual for the Takeuchi TB145 I own and have spent about 8 hours trying to track down the problem. The valves out on the stick are turned on. If I take the hoses off the thumb and start the machine, it pumps hydraulic fluid freely out both sides; so flow is not restricted. However, I get NO voltage in the connection in the thumb controls on the left joystick. Further, when trying to trace it back to wherever the issue may be, I noticed I have no voltage at all at the 15 amp fuse block in the fuse area. So, I'm not even getting power to the fuse block for the operation of the thumb. Where would I go (backwards) from there to see why I'm not even getting power there when the key is on? Everything else works just fine on the machine. I don't even have a single light that doesn't work. Help! This is driving me nuts!
It shouldn't pump fluid out the hoses unless flow is sent there, and flow operates the cylinder. Did you switch the stick from hammer mode to attachment mode? As I understand that lever switches the maches from one to two way aux. hydraulics. Is it working properly, but the reliefs are turned way down? - I'd think that you would just have no force if that was the case though.
The shop manual said that with the lever NOT in hammer mode, I would get flow through either hose. That way both sides of the piston in the thumb cylinder have slight pressure to keep it from moving any. All of that worked normally. It's only when I need the solenoid to activate in "A" (open the thumb) or "B" close the thumb that I have the problem. I have no signal going to either solenoid to open the flow either way. The troubleshooting guide said to check the top right 15 amp fuse in the fuse box. It wasn't blown, but the meter shows it never gets power; key on, no voltage; hitting either button, no voltage. It appears that my problem is somewhere between my power source (battery) and the fuse box. Problem is that all those wires are heavily enclosed and I see no easy way of even getting to the back of the fuse panel.
When happens when you jump power to the outlet side of the fuse?
I would feed power to the inlet side of the fuse, that way you still have a fused connection, in case there is a problem down the line. Also disconnect the original wire going into the fuse because if it has shorted out and been disconnected, applying power to it might be trouble. Also if you have very limited experience with electrical stuff, I would advise to get a auto sparky to check it out.
Our Takeuchi have a valve that switches from one way flow to two ways flow
That's what I've been considering if I could only get to the back side of the fuse panel. I cannot even test the solenoids for the thumb if they are not getting actuated. I cannot test the switches in the joystick unless they get poser to them; which they are not. This unit is exceptionally clean for a 2006 model (residential use only), so I'm scratching my head trying to follow the service manual manual wiring diagram and see where there may be a problem. All I can think is that somewhere inside the enclosed wiring harness perhaps power to auxiliary power solenoids operated by the joystick controls came unplugged or somehow got broken. According to the service manual, one of the three main fuses just above the battery would blow if I had a short in that portion of my wiring harness, which is not the case. Besides, everything else works; right down to all the travel alarms and every single light. The manual just said to make sure I don't have it set to "hammer" at the valve just ahead of your right foot as you are sitting on the machine; check. Then make sure the valves on the boom are open; check, and they moved easily. I keep feeling it's something simple that I'm missing but I'll be darned if I can find it. I really don't want to cut open all the wiring harness covers, but I also don't want to take it in to the dealer and have them charge me a thousand bucks or something worse only to find that there is a plug somewhere that got unplugged. I may feed power to the back side of the fuse panel for that fuse if I can get to it. Heck, as far as I know, that may be where it's unplugged.
Can you get at the aux hyd solenoid easily? Perhaps wire it up directly from the battery with a inline fuse and a couple of switches. Do you have power going to all the other fuses?
Well crap. It was just a loose ground to the fuse panel at the top causing what seemed to be no power to the aux hydraulic circuit. Fixed that, but made no difference. I spent 4 hours with the workshop manual following wires and testing every voltage and ohm reading I could to no avail. I guess I'm screwed and will have to take it to a dealership.
Do you mean flow comes out both ends of the hose you disconnect or you disconnect both extend & retract hoses and get flow through each circuit? Do you have couplers with flow checks in them? Bleed the thumb cylinder? You mentioned this was a residential unit.Privately owned/maintained? I'd check for "repairs" or modifications also. HTH Jay.
There have been no repairs to this machine, only scheduled maintenance. However, I did finally solve my problem after hours and hours with my meter and the repair manual. Apparently Takeuchi uses a rubber coated thin piece of metal to fold over wiring within the machine. It just so happened that, in testing continuity of every wire, one wire failed. After hours of looking, I finally found where it had rubbed against a place where this metal tab holding wiring in place had vibrated enough to wear through the rubber coating on the metal tab and the covering of the wire, causing a short. Once I repaired that problem all immediately began working just fine. I'm really glad that it didn't cost me anything to fix this problem, but it sure was aggravating! Thanks to all who offered suggestions.
job well done.