Hi everyone, new to this forum, glad to be here. hope to get some advice on my hoe issue. its a 410D serial num T041DG819318 It started with the warning light for voltage a few days ago, at first I noticed it came on after I ran it for an hour or so then turned it off and back on and no light, but came back on after I ran it for a while more, now it stays on and I noticed the mfwd is not working so after looking I saw it had a blown fuse and blows each fuze instantly soon as it gets power. I swapped the relay with a known good one to no avail, also the tach is off but fuel gauge is working wipers and lights work fine, I swapped the alternator and same prob, so now I am thinking after noticing the mfwd is not working if that solenoid failing can cause voltage issues like that and blow those fuses, I had a look at the 2 wires to that solenoid for tears or what not and it looks ok, at least the part I can see, it runs over the top of the trans where I cannot see that part, any advice on this would be great, I have owned this tractor for 3 years now, it is a beast, sort of a jack of all trades, dont know what I ever did without one before. thanks for any advice.
Try disconnecting the wiring at the solenoid. If the fuses no longer blow, there is your problem.
Thanks for the reply, I should have mentioned I did that also and that fuze still blows, the wires in the wiring harness from the mfwd switch looks good but are untraceable because as I am sure u know they are in a huge bundle of wires, I am scratching my head as to why if there is a prob with a mfwd wire or component then why is the tach not working as a result of that, the dash light that is on says VOLTS,ALT which would explain the tach not working as it plugs to the alternator, I did buy a new alternator and install it and the prob did not change, I am wondering now if the alt I bought was the wrong voltage or something, this is the one I bought for it, https://www.ebay.com/itm/New-Altern...e=STRK:MEBIDX:IT&_trksid=p2057872.m2749.l2649 I found them from about 60 bucks to 250 bucks, not sure what the diff was that would make such a big cost difference on them. I put the original alt back on it since it did not make any diff with the new one, I may end up having to call Murphy tractor out to have a look at it. Any other ideas?
Update So the fuse that keeps blowing is hard to read the label but it looks like it says ALT,MFWD,DIFF LOCK so I will check for a solenoid or something for the differential lock, It blows instantly when the key is turned even with the mfwd dash switch off, but still keep thinking the tachometer not working is telling me its an alternator issue, maybe someone more knowledgeable can tell me if that sounds right, can anyone tell me what voltage should be coming from the alt, I assume the little black wire that plugs into the back of the alt is for the tach, it has a small ground bolted on the back and another wire on a 5/16 post on the back besides the main (bigger) wire on the 1/2 inch post & bolt, would be good to know what all 4 of those go to and what they should test out at, thanks in advance for any help
Sounds like you have a short to ground. If you are savvy with a volt meter then you should be able to find it fairly quickly. I would put my meter on continuity with the buzzer function on. Then take one lead and put on the side of the fuse that doesn’t have voltage and then put the other lead on a good known ground. If you have a short to ground then your meter will beep continuously at you. If that happens then start unplugging the harness at each component that the fuse powers. If and when the beep stops then the last thing you unplugged is causing your short to ground. If you unplug everything and your meter is still beeping at you then somewhere the harness has rubbed through and is touching frame. That’s when you will have to roll your sleeves up and start removing panels and things and chase that harness around until you find the damage. Good luck. A wiring schematic would be very helpful and make it easier. But it can be done without.
The only thing the F1 MFWD/ALT fuse powers is the MFWD switch and the D+ terminal on the ALT (Diff Lock on that machine is mechanical). Unplug those two and the fuse still blows then it is a short to ground in the wiring someplace.
Hi mg2361, thanks for the reply, I do have the mechanical pedal for the diff lock at my left foot, but the fuze does say diff lock, I guess it is electrical on some other models but they must share the same fuse block with the same label on all of them. I will try to unplug D+ from the alt and correct me if I'm wrong but leaving the MFWD switch off is the same as unplugging it? I only ask because I do not see a way to unplug either wire from that switch without just cutting it then crimping it back together, thanks for the help
The four terminals on the back of the alternator are B+ out (the large one) and should read about 14.5V@ 1000rpm.The other three are the AC pulse to drive the tach., the sense voltage to light the alternator charge lamp on the dash when the alternator is not charging properly and the excitation terminal that needs 12V (voltage should be present as soon as the key switch is turned on) to make the alternator work.They should all be labeled.I just recently swapped out my alternator and even though the new alternator was very similar in appearance to my original the wiring terminals on the back were set up a bit different so you have to make sure you're hooking it correctly.
Just unplug the mfwd switch in case there is a short in the indicator light circuit inside the switch.
Thanks for all the input guys, I am going to spend some time with it this weekend, I will report back, thanks
OK so I unplugged the MFWD switch and light and the fuse still blows right when I turn the key to power. So I am thinking it would be easier to just run new wires then try to hunt down the short, the problem is I do not have a wiring diagram and those wires are in a pretty big bundle, that harness is about 3 inches around with about 50 wires in it so I cannot follow it, does anyone have a readable wire diagram for it or can tell me where they run to? thanks for all you guy's help, also was thinking is it possible the alternator can cause the fuze to blow like that ?
Schematic attached.
Thank you so much for the diagram, so at the risk of sounding stupid and just to be sure because I am no expert, tell me if this is correct, it looks to me that I most likely need to replace the wire "P13 RED" in that diagram that goes from the MFWD switch to the alternator D+ pole, and if that does not fix it then maybe try to replace B15 red that goes from the switch to the relay, that diagram does not show where B15 red goes on the other end, do you know? thanks again for the help
I guess I need to pull the D+ wire off the alternator and check it to make sure that fuse does not blow before I replace the wire, it still blows with the MFWD switch connector disconnected but I have not tried it with the D+ disconnected from the ALT yet.
Yes, make sure you disconnect the D+ wire first. To answer your question, if the fuse still blows with the D+ disconnected then just replace the P13 red wire that goes from the F1 fuse to the MFWD switch and to the D+ terminal. B15 wire short would not blow the fuse. Fuses will only blow from something shorted "downstream" of them.
Update So the fuze does still blow instantly when the key is turned with the D+ wire disconnected from the alternator. So I pulled the fuse block loose and inspected it, it looked OK, the wires going to and from the MFWD switch and the fuse and relay all look good no cracks or visible issues, the wire going from the switch to the fuse looks new and I am sure it is not the problem, so I guess my next step will be to cut the P13 RED wire at the switch and run a new one to D+ on the ALT I will do that tomorrow and let you know how it goes, hopefully, no warning light and front wheels turning, I can't believe how tight, neat and well routed all those wires are in there, I had to cut 5 or 6 zip ties to gain clearance enough I could get the fuse block to turn over. I was gentle as to not mess up any of those plastic seats the wires feed into the back of the block. thanks again for the help
wow.. you would think that something this in-depth would be a known problem & written-up somewhere on the web?
You would think. John Deere actually publishes a solution for MFWD fuse blowing. If they publish a solution then it must have been a fairly frequent issue.
Question for someone that knows. The P13 RED is a small wire, the schematic shows nothing in-between the switch and the alternator, however, the wire on the D+ pole on the alt is a much bigger black wire, it has markings on the alt that shows D+ so I know I have the correct wire, so the question is where or why is it interrupted and why is it not on the schematic? obviously, it is not a home run from the switch. The machine is here so I should trace it to find out why myself, which I will do but wondering if anyone knows , if it is interrupted within that big bundle of wires I will not be able to know where it goes
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That little wire just below the D+, what color is it and what is the number on it. Also what is the number on the black wire, I can't quite make it out in the photo. Looks like it is G02. If that is the case then the Alt is wired incorrectly. G02 belongs on the frame of the Alt and is usually attached to one of the tie bolts that hold the Alt halves together. That wire below the D+ in the picture looks "reddish" and if it is the P13 it is shorted directly to the Alt frame.
I did change the alt out 2 times once to the new one I bought and when it had the same prob then back to the old one but I took pictures so I would not get the wiring messed up. I am at work now, will look when I get home tonight to verify it, thank you for taking time to help me!!! EDIT: also its worth noting that the small one with the cap on it I think has to small of crimped on end to fit that bigger D+ post, going from memory but I think that is correct, will find out in a few hours.
So I did have the 2 wires switched on the ALT from ground to P13 so when I returned them to their correct positions the MFWD worked again but the ALT warning light was on again, so back to my original problem, so I swapped the alternator out again with correct connections and all is good now, the batteries are charging again and ALT light is off, I did refer back to the original picture I took so I would not get the wires confused as to where they went when I replaced the ALT the first time, not sure how I managed to mess that up, unless maybe it was the beer, LOL. (I feel dumb) Thank you to everyone in this thread who helped and offered advice, pretty much everyone was right on, great forum here. especially thanks to mg2361 for the advice and the schematics. Problem solved, mods can close this thread if need be thanks again!!