Hi all - Just registered on this forum, but have been lurking around here for quite some time. This is a great site and I actually found the info here to diagnose and repair the charge pump on my Case 850D dozer. Thanks for that, now on to a new problem that I hope someone can help with. I have a 97' Deere 310SE hoe. About a year ago it started blowing the fuse on the forward/reverse lever whenever you tried to move it. After talking to John Deere techs I replaced the F&R lever (400.00 some odd dollars) and that seemed to correct the issue. All has been well until a few days ago, while plowing snow, it started to do it again (once in awhile) and has gotten progressively worse to the point where it blows the fuse as soon as you move the lever. I have looked at the contacts on the switches inside the lever, everything appears clean (and dry). I started to trace the wires from the switch looking for a bare or pinched spot. Have not found anything, but it is hard to follow the wires as they weave in and out of sealed looms. I have traced some of the wires down to a set of solenoids on the trans. Does the F&R lever control solenoids to change transmission direction, and if so, is it possible a bad solenoid could cause such a short? I have a technical manual for the machine but it has not been much help. I would greatly appreciate help or feedback from anyone with an idea of what to look for. Thanks, Scott
Welcome to the forum Prink. :usa Haven't worked on an SE myself, but it's very possible the problem is a failing solenoid. Yes, the fwd/rev lever sends voltage to solenoid coils on the tranny to control transmission. What voltage is the fuse it's blowing? Let's say it's a 15 amp. Get a 15 amp thermal circuit breaker from a parts store, rig it with some wire terminals so it connects in fuse panel instead of fuse while testing. Engage your fwd/rev lever, see if it pops the thermal breaker. Once it resets, disconnect the harness where it connects to the solenoid coil. Try lever again, see if it pops breaker. If it does not pop breaker now, probably got a bad solenoid coil.
Thanks for the info Atco. Tried the circuit breaker trick (10 amp) today but couldn't get the damn thing to blow. Reinstalled the 10 amp fuse and everything seemed fine. Test ran the machine for 15-20 minutes and could never get the fuse to blow. Yesterday it would not move, blew a fuse everytime I moved the F&R lever. Is there any other way to test the solenoids? Hard to diagnose the problem if it won't stay consistant. This is starting to get aggravating, as I have job to do this week, but am worried this will start acting up again. Thanks.
You can take the solenoid off put power going into it, doesn't matter which way is positive, and put a screwdriver in the middle, when you send power to the solenoid it sends a magnetic force to grab the valve, if it doesn't grab the screwdriver its a bad solenoid. It may not be the best description I gave you, but e-mail me if you want and I can try to explain it better.
Trust me, I know, been working on machines for years, #%&^ things will never do it when you want them to. :Banghead Typically, but not always, when solenoid coils short out and start blowing fuses, they don't all of a sudden start working proper again. Sounds like you may have a spot in your harness that is hitting ground occasionally. Man those are hard to find. If nothing else, for now until you discover the problem, leave the circuit breaker in there. It will protect your wiring when it acts up, and you won't have to keep replacing blown fuses.
Does your unit have the clutch cut-out on the gear selector (not the F&R lever) or is it a newer style unit? I have had to r/r those many times on rental fleet equipment, the switch goes down through the lever and out through a small hole in the bottom(bad about rubbing). Intermittent electrical issues can be a bear at times.
Are you possibly getting snow up around the solenoids and it is melting and shorting out? The clutch cutout solenoid is another good possibility as well.
The disconnect is probably on the loader control, sorry for the earlier info.
Cosidered that, but when I took the cowl off to trace wires everything was clean and dry. I think it would be hard to push snow up that far. The first time this happened was about a year ago, during the summer in dry conditions.
My clutch cut out is on gear selector not f&r lever. When the fuse blows it sets the park brake.
Check the cannon plug for the wiring harness, (it has been awhile since I worked on any deere equipment except installing 4rth function controls for a customer so I am not certain of the exact location) seperate the plug, I believe it has a twist lock nut. You can check for loose pins/corrosion, then you can ohm out the wires to the solenoids. Did you ohm out the solenoids yet?
What should the resistance be on the solenoids? How about through the lever itself?
I normally consider them OK if I get 12-28 Ohms. As for the wires, you should have good continuity (at or near 0 ) through the wires from the switch to the lower connection, then after you verify continuity, double check it by connecting the meter to the lower connection 1 wire at a time and verify no wire to ground continuity with the key off. If the unit has an ECM that monitors or controls the brake and clutch cut out functions you will get false ground readings with the key on, for this reason to check a circuit properly the wires must be disconnected from all components and then checked, that way you know you are getting an accurate picture of the wire itself. Same for the solenoids, disconnect them prior to checking.