Hi people, Needing some help with this backhoe it is a JD 410D serial num T041DG819318 my issue is everything was working fine until a few days ago, at which time when I started it up the tach did not work and the dash switches did not light up when switched to on like they always have, such as the brake light, the mfwd light and others,I lifted it up and it appears that the front wheels are turning, the horn button works the wipers work, it starts and runs ok. The yellow ! and alt/volts STOP/danger light is on. Here is what I have done I have a spare (new) alternator which made no difference, and yes I have double checked that it is wired properly the new one is on there now, I have checked the fuses all are good and have checked the hot side of the fuses for the mfwd and tach and they have power to one side when the key is on, I traced the wiring harness coming off the alt as far as I could see it and see no issues in that part, there is one wire that is weathered and broken, it connects to what feels like a sensor (I cant see it) it is right behind the valve cover in front of what on a car would be the firewall, I am guessing it may be a cam sensor but not sure, I put it back together and it made no difference. there was a squirrels nest on top of the motor and I know what that means but I see nothing chewed thru and those fuzes and there switches have power, also I did change out the alt relay to no avail, I looked thru the forum and did not see anything regarding this on a 410D, I appreciate any help thanks guys/gals. The picture is with the hoe running
I am digging deep back in the memory bank for this one; There is a pin on the alternator that picks up a pulse off one pole of the stator that makes the tach work.Is the alternator charging? And what kind of alternator is it,Bosch or Delco?
That link is the one I bought, and keep in mind I have had 2 alts in there and it made no difference so I am thinking that eliminates it being a prob with the alt. I forgot to mention I did also unbolt that fuze block and inspect behind it, and it all looks ok, nothing worn or broken at least visually. I assume the alt is charging as I have run it some and the batts do not seem drained at all, but I will check voltage from the alt and report back. https://www.ebay.com/itm/New-Altern...e=STRK:MEBIDX:IT&_trksid=p2057872.m2749.l2649
So after reading delmers posts from this thread HeavyEquipmentForums I am needing/wanting to check that starter relay as he was saying it has some control over accy's, does anyone know if it is bad can it have some effect on the tach? and anyone know a part number for it my machine is JD 410D serial num T041DG819318
Pull the dash panel out, there is a accessory relay in there, looks like an old ford starter solenoid. it sends power to some of the fuses. when running both big post should have voltage.
I do remember having accessory relay problems but I think the problem may be in the wiring.The alternator may be new but if there is nothing to tell it to start charging then it will not charge.We did have problems with the Delco alts and we replaced them with Bosch. First thing to do is to get yourself a volt meter because you can't properly diagnose an electrical problem without it.I will send you a few schematics that may help and don't be intimidated by electrical because there are 40 to 50% of licenced mechanics that don't get it either.Your problem may be a bad alternator relay.
Try swapping the alternator relay with the ether aid relay
I already replaced it, I keep extras on hand, it made no difference. I saw that relay behind the fuze block, ya it does look just like an old ford starter relay I just wasn't sure what the small & large wires should have in the way of power so I could check them, If I can find a part for that relay I will buy a new one, I see on ebay there are many different part nums that all look just like the one on my tractor, Ill try to get at it from the cab side instead of the window and maybe I can find a part number on it, we are getting 5 inches of rain today and tomorrow so will have to wait until fri to check power to it unless it lets up sooner. thanks for the advice guys I really appreciate it, and where are you getting the wiring diagrams, from the service manual? I need to get my hands on one if so.
If you have a volt/ohm meter I may be able to walk you through what to check. The schematic I sent you was from a 310D but they should be the same as the 410D.And if you have an old ford relay it will work and its way cheaper than what Deere will sell you.Grab ahold of the relay and turn the key on.You should feel a thunk.If not then check for voltage at the small gauge wire going to it>
Also check the mfwd fuse and the diode to the alt harness.As I remember they are in a group of three taped together .
I have a meter, and the mfwd fuse is good and all 4 wheels turn when on but no light at that switch anymore, the 2 rows of fuzes-- the bottom row all have power on the top terminal and the top row all have power on the bottom terminal, but none have lights anymore neither does the brake switch but all those switches seem to still work, just no lights for them and no tach
Bad ground?
accessory relay part number AR73144 ( ALSO ORDER (2) 14H785 AND (2) 12M7065) nuts
On the way,I found one with the nuts https://www.ebay.com/itm/SBC4201A-1...e=STRK:MEBIDX:IT&_trksid=p2057872.m2749.l2649
What does your volt meter say in when you connect it to the alternator when the machine is running?Is it charging?
Ok so our rain event is over now and I got a chance to get back after it, the alt is charging but it is a 95amp alt but my meter shows 120 amps dc coming out of it when running, and the solenoid behind the fuze block has power at both of the large poles and the small one when on, when off it has power at one of the large ones, so it seems fine, it does thunk when the key is turned, I was unable to locate any diode, where would it be located? Also I checked the alt fuze again and when I pull the fuze and check the receptacles that the fuze goes into one of them does have power, seeming to me (and I am no expert) but could it be a ground problem? and how to check that ?
Thats something I have never seen ,120 amps coming out of a 95 amp alternator.I would check it again with the engine running and check battery voltage.If you get battery voltage at both places then the alternators not charging.And make sure your meter is set to volts not amps. The diode should be near your alternator harness.To check the diode put your meter leads on the two poles of the diode .with the meter set to ohms swap the leads.You should have continuity one way and none the other.
My meter is one with a needle and not digital, I may have been reading from the wrong line or something and the engine was running when I checked it, Ill do it again in the morning, I have a digital meter somewhere but I cant find it at the moment Do you mean by battery voltage 24 volts ? Thanks for the diagram it is helpful.
Update: I get 95 at the batteries and the alt, and from both the big wire on the alt and the second biggest wire on the alt. hopefully I have the meter set right, it is on volts and set to 50 see pic below, it registers where I have the red arrow in the pic I checked the diode but just realized I did not have the meter set to ohms, it was set to volts and showed 95 on both wires I will go out and check it again with the meter set to ohms.
Yikes.That meter is confusing.It will still get the job done but if you don't know what its telling you then it is useless. Get on amazon and buy your self a digital meter!You can get a half decent one for about $25. This thing shows 15 volts dc where you have the arrow pointing.And it is a 12volt system with 2 batteries in parallel and that is where you should start.Check battery voltage with machine not running and then with your meter still hooked up to the battery start it up.If the alt is charging you should see the volts start to climb to about 14.2 volts. Like I said before;there are a lot of mechanics out there that do not understand electrical but once you get it you get it.I teach HD mechanics at a local college and it is one of my favourite subjects .Think of a garden hose; volts is pressure,amps is the flow of electrons(water) and ohms is the kink in the hose.
Joe's correct. Definitely get yourself a digital meter, way easier for the novice. Once you go digital you will never go back . I still have one of those analog meters somewhere in my garage in storage. Probably been sitting there for 35 years now.
@ mg2361 Thanks for the clarification on that, I will find a digital one
A digital multimeter is $3 at harbor freight, nothing wrong with them except they don't tolerate water as well as a good one. The other thread was a loose ground wire, as far as I could tell. Checking the voltage at the logic module, ignition switch, relay etc. will show you what's wrong. BUT, ONLY if you're reading the voltage that each component is seeing, by measuring it's hot and ground. They all need BOTH.
What does your volt meter say in when you connect it to the alternator when the machine is running?Is it charging?
OK I found my good meter, it shows 14.3 at the battery and the alt when the hoe is running see pic below I assume this is the diode behind the alt maybe someone can verify it by the pic below for me,(sorry about the watermark) it shows voltage one way and when I switch the leads from my meter around it then shows 0.0 then after a second or to goes to showing OL. Also with my machine running I get 14.3 Volts at both of the leads with the red arrows in the pic below So the logic module is the little flat box about the size of a flask behind the fuze/relay block in the consol, is that correct? so I guess that is my next move is to check that, can I ask you is there anything special I need to do to check it, I assume I will need to know what wires go to what component coming out of it, sorry for all the questions.. Was so much easier when it use to just be a timing light and a set of points lol......
if anyone may have a diagram of the logic module's wiring and the proper voltages for those wires I could sure use it, thank you guys/gals for all the help so far, this backhoe it is a JD 410D serial num T041DG819318
Now we are cooking with gas !! I will send you some info.The manual I have is for a 310D but they should be the same.If worst comes to worst and you can't find the problem then get some duct tape and stick it over the yellow flashing light on the dash.As long as its charging you should have no worries.I have found so many electrical problem just by pulling harness's apart and plugging them back in.Follow the harness and check the pins and get some contact cleaner and clean each one as you go.Good Luck!
More info
Also grab each harness and shake it with the engine running, you might just get lucky.
Ok will do, this is driving me nuts, its like an itch I cant scratch, the worry with the duct tape is that alarm may be needed for something important later and not available to warn me, like fluid related and that could cost alot of $ to keep operating thru that I think EDIT: Oh and I forgot to say thanks for the files and advise my friend!
Also another question, this may answer its-self when I get that module out and have a look at it but is there a way to look up the part number for my logic module? I am sure its probly expensive but would like to look at just replacing it as well, thanks. this backhoe it is a JD 410D serial num T041DG819318
Just asking the relay for the alternator is 6 volt right, all other are 12 volt. Have you ever used scribd.com, it has a complete test book for a 410D for viewing. They may have a free trial, I have used the site it for years.
You are absolutely right chisumtrail.It is powered off of the r terminal of the alternator AC volts .It would explain why the tach is not working.I had a similar problem with a 690E;24 volt system-12volt alt relay.That little mother would be a special order from Deere.That is the first thing I would replace.Now that we have established the thing is charging!
are you guys meaning the black square relay in the fuze block?
Yea it should have 6 volt stamped on it. The M39 purple wire that plugs in back of the alternator splits and goes to the prong 86 on relay and and tach. The power out of plug should be about 7 volts AC and you should have same voltage at 86 on relay and tach.
Update: so I switched out the alternator back to the old one again and after I did I noticed I switched the G02 wire and the P13 wire by not paying attn enough or shear stupidity, but I did notice it and corrected it but my question is shouldn't that have blown the alt fuze and or the mfwd fuze since it was on? because it did not blow any fuze and I did start the tractor with them switched.
The diode may have kept the ground from coming back to the fuse.
Since I retired I teach HD mechanics at a local college and I tell my students that there are no mistakes in my class,only learning experiences .
Right on, I appreciate all the help, I know you cant beat a guy at what he does, love this forum its a great place for help. Last year or maybe 2 years ago I replaced the alt and got those same wires switched I know it blew the mfwd fuze instantly, I even made a post about it here, so let me ask you this, why did it not blow it this time? just wondering if that should tell me something about my current issues?
The wire has 12 to 14 volts now?
the mfwd is working, verified by putting the tractor in the air and spinning all 4, the light does not work for any switch now but the switches seem to all work, and the alternator's 2 + post's with nuts both read 14.3 volts when the tractor is running which wire are you asking about?
The P13. Did you check the M39 purple wire?
P13 has 14.3 volts and I am on my phone and cannot look at the diagram but if the M39 is that slip on plug for the alt no I did not check it's voltage but both of the ones + one's with nuts on them get 14.3 Volts
The slip on wire is signal for alt light and tach.
OK what should voltage be for it or should I just check for voltage? I will check it in the morning
7 volts AC
Yes, just checked it and it shows 7.13
That wire goes to prong 86 of alt relay (the 6 volt relay) and tach, you can see if the same voltage is there.