8/28/2012 8:08 AM
Ryan,
This is copied from another forum and may help. They are working on a 3400 but I believe the controllers are similar, or the same, and also many of the other features as well. Sorry for the long post but all good info.
Lf3400 not turning reels
2005 lf 3400. Issue is reels do not enage when lowered. This happens after mowing for a couple hours. Occasionally reels will disengage while mowing but usually they never start when lowering. Letting the mower sit helps which makes me think somethings heating up. The light on the module for mow solenoid goes out when its not working. I have swapped solenoids with no result. One of the solenoids was pretty rusty, but it was on the backlap side. Thought previous mechanic might have swapped them previously so I swapped a different one issue still exists. All reels do not engage which I thought only front or back would if a coil went bad. I am not sure where else to look at this point. Bad module? Has anyone had a mow valve go bad? Any advice would be appreciated.
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I had this same thing happen to me on my 2005 LF3407 (same thing just 7" reels), after a VERY long time I finally got this figured out. I went through the solenoids like you did but you are right, the front and rear are separate and should only shut down one of either sets. I also checked the harness and all the other good stuff. One other good possibility would be the proximity switches on the outside two reels. My main problem with mine was that the machine wouldn't do it regularly enough for me to replicate the problem in the shop. The operator would run into this issue and solve it by lifting and re-lowering the cutting units and then they would engage, 99 times out of a 100. Finally I got it to do it for me one day out in the field and noticed that I had all the proper inputs needed for the mow solenoid output to be active, but it wasn't, so I questioned the actual control module. I replaced it and problem solved, turned out the controller had a crack on the case and it got water damaged, but still about $1000, more if you overnight it.
I didn't have another machine like this one that would be compatible to swap controllers, but if you do, and if it comes down to that, give them a swap.
Hope this helps.
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I agree with xxxxxx. arm prox switch connections then possible controller. A little trick in the Controller... If your controller is a newer style (lights on the front not on the top) you will see the circuit board is submerged in an electronics resin. Try this.. With someone sitting on the seat and with the park brake off engage the reels while sitting still. Then take your finger and press on the resin material to the left and right of the Mow solenoid LED light. See if the mowers kickon and off.
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Troubleshooting tips mow circuit 3400
The Controller has circuit protection built into it. In the event of a short in the wire or mow coils, the controller will not send power out to the front and rear mow solenoids. Depending on your vintage(Typically newer style controller machines) the controller power goes directly to the mow coils. On the older units the controller output will go through the Mow/Reel directional switch which directs the controller current flow to either the forward or backlap coils on the blocks. You can swap the coils for Mow and backlap to rule them out on the front and rear mow manifold/valves. (Inner coil on front Manifold Outer coil on Rear for Mow) Each coil will likely read 5.5 ohms or so of resistance. You can check for harness shorts/opens with all of the coils hooked up and wiggle the harness(s)(On older 3400's typically (with lights on top of the controller) put mow switch in mow position and unplug the green controller plug look for gray wire with green tracer and hook up your ohmmeter between the controller output wire to the mow coils and ground). On a Newer style controller perform the above steps but you will hook to the Gray wire with Orange tracer and mow switch is position is irrelevent if you have the red mow knob) Keep in mind all mow coils are wired in parallel so you will have to use a simple math equation to figure the circuit resistance. on a 3400 there are two coils one for front reels and one for rear circuit (assuming each will be 5.5 ohms) the mow circuit ohms should read approx 2.75 ohms as seen by the controller. If you are powering 3 coils the resistance would be 1.83 ohms. To see this in action with your ohmmeter hooked up at the controller output wire unplug a mow coil and you will see your resistance value increase.
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Got through one day with no problem. I installed a relay on the mow solenoid wire. Which according to the dealer takes most of the load off the computer. He says they have had luck with this working for a long time. We'll see how it holds up.
Bret Hart
Equipment Manager
Turning Stone Resort