Hello guys, I need help with my 40e jlg. I was getting the manlift down of my gooseneck trailer, and it went down very fast like if there were no brakes on it. I got really scared. I checked the motors and they seem to be Ok, but there was a 10 flash code on the sevcon. The 10 flash code means: speed encoder failure. I went to the manual and says the tachometer is failing, does any one know where the tachometer is located? Thanks!
View attachment 96196 from this previous post : "When this model was introduced, 1996, the Creep Switch (snail) was not on the machine. The issue at the time was when truck drivers were unloading the machine on an incline, the unit would freewheel down the grade a bit before the Plug Braking (dynamic) would kick in. This was un-nerving to say the least! Many resourceful drivers found that if they elevated the tower (lower) boom enough to get it off the limit switch, the machine would come down the grade nice and slowly. JLG then went ahead and installed the Creep Switch to achieve the same results and to facilitate easier unloading." and: "The tach generator is the appendage attached on the left drive motor. It is an analog voltage device not unlike the generators that used to rub against a bicycle tire to generate a voltage to light a headlamp/taillight. It is very easy to test. It puts out approximately 20 volts per 1000 RPM (if memory serves correctly). Spinning the shaft in one direction will produce a positive voltage and spinning it the other direction will produce a negative voltage. To test, simply remove the generator from the drive motor, place the shaft of the generator into a reversible, variable speed drill. Note the color wires that were connected to the generator and remember the post numbers they are on. If the wires are interchanged, the motor controller will be confused and think the machine is running backwards. Connect the positive and negative leads of an analog-type voltmeter to the two terminals the wires came off of. A digital meter will work but the needle of an analog meter will show a nice smooth sweep across the meter face and better reflect any bad spots where the generator is putting out a sporadic signal. While observing the voltmeter, slowly increase the speed of the drill and check for a smooth increase of the voltage output of the generator. Also note the polarity of the voltage. Slowly decrease the speed of the drill and note the smoothness of the voltmeter as the generator slows. Reverse the drill direction and repeat the test. Be sure the polarity is opposite that of when the generator was spinning in the other direction. It is very important that the voltage from the tach generator has a smooth increase and decrease movement and is reflective of the speed and direction of the generator shaft. The tach generator is used to tell the motor controller how fast the machine is traveling and also the direction it is traveling in. When you are scooting across the floor in forward, for instance, and the joystick is released back to neutral, the tach generator is telling the motor controller what direction the machine is traveling (by the polarity) and how fast the machine is traveling (by the potential). The motor controller at this time will disconnect the forward contactor and activate the reverse contactor and use dynamic braking (plug) to slow the machine down to a stop. When the machine reaches a full stop and the motor controller senses no movement of the drive motors, it will then release the brake contactor, letting the parking brake apply. If the motor controller is sensing erratic signals from the tach generator while driving, it starts flipping back and forth between the forward and reverse contactors trying to regulate the speed and direction of the machine. The signal from the tach generator is also used to regulate the high drive speed of the unit. The generator can be cleaned to reduce this erratic signal. Being very careful, remove the wires attached to the small terminals of the tach generator. Real Careful. There is the nut, a small washer, the wire end, and than another hex-head stud (that the wire was attached to) that has a spring and brush attached. Carefully remove the two brushes from the generator and set aside for re-use. Remove the other small screws holding the end plate of the generater on. When the cover is removed, a metal disc that the brushes rub on will be visible. Clean this disc with a solvent such as brake-clean. Reassemble and test again. Be very careful re-attaching the wires to the generator studs. The threaded part of the stud is very easy to break or crossthread. The tach generator is an analog component and the motor controller is digital. There is an interface board between the two that converts analog to digital. This is the small board located to the left of the motor controller. Check the connection and make sure they are clean and secure."
Tanks a lot Voodoomojo, i Will follow every indication you gave me. Right now the manlift drives forward just for 2 seconds and stops immediately, the same problem on reverse. I hope i can get the problem fixed today, thanks a lot!
Hello VoodooMojo, this is Lico and I have another problems with manlifts, I hope you can help me this time again as you did last time. This is the problem, I have a JLG 600AJ year 2002, it has a Ford 2.5 lt engine, it was working well but suddenly one day when I turned the engine on it turned off after a few minutes, after being checked by several mechanics finally one guy told me the problem was the fuel pump, the fuel pump that is on that equipment it is a "Bosch", it seems to deliver 45-50psi. I could not get a "Bosch" fuel pump so I got a "Federal Mogul", when I installed the new pump it worked well for a couple of minutes, then the fuel pump gets really hot and the pressure goes down! The new pump delivers 110psi, I want to know if I need to get a fuel pump that delivers the 45-50psi or if there is something else wrong, the gay in the auto store says fuel pumps must deliver 85-110psi, but the pump gets hot and stop working trying to deliver the 110psi. I hope you can help me out with this problem, thanks!!!!
Hello LICO! Did you ground the fuel pump directly to ground? I am on the road at the moment and dont have access to a schematic but the engine ECM should supply the negative to the fuel pump. Connecting it directly to ground will disable the computer from being able to control the fuel pump. I will respond with more detail this evening when I get to a hotel.
Voodoomojo, I used the same wires that were connected to the original fuel pump. Thanks for your help, i will be waiting for your answer tonight, thanks!!!
Lico has started a new thread about the 600AJ problem, which is a good idea as it's a different machine than the 40E which this thread is about. Please respond about the 600AJ at the new thread.