[rwall10597]

I just went out to run the tractor down to the street and it was stone dead, thats never happened before, Its been low a few times when I let it sit a few months, but I've only had to get the charger on it a few times.

Something is wrong, I put the charger on the battery, and still nothing, no lights etc... I got the multimeter out. The battery has plenty of power, its grounding to the frame, and I've got positive to the 30 amp fuse. I ran out and got a fuse, (apparnetly I'm the only guy in my town to need a fuse in years so they were oddly hard to find). I stuck in and zap, $5.29 burned up instantly.

Any ideas? I ran it a bunch last weekend without incident. The lights won't come on or anything, its just stone cold dead.

 

[gwest_ca]

A heavy short like that should be easy to find. Instead of blowing more fuses remove the fuse from the holder and connect a test light or voltmeter between the 2 fuse leads. As long as the short exists the light will light or you will show battery voltage on the meter. Move wires around and disconnect and reconnect one item at a time until the light goes out. That is where the short is. I like using a light because you can watch it out of the corner of your eye as you work.

You can also replace the fuse with new but disconnect the negative battery cable first. Then connect the test light or voltmeter between the battery and the cable you just removed. This is the better way to do it - checks everything including an ammeter.

What is the tractor's model number? A wiring diagram may help.

Garry

 

[rwall10597]

Its a 417-A. I have all the exact numbers and PDFs on my work computer but haven't gotten that far into it yet. I just went out and messed with it without the help of my 6 year old. Apparently the fuse didn't blow again. I need to pull the diagram up I guess, but there is something with two wires coming out of it that looks nasty, and one of the wires was coming off. My initial uneducated guess is that its a safety switch for the PTO. Nothing has been on the PTO in at least 12 years, so I think I'm safe if I bypass it, IF thats what it is of course.

 

[rwall10597]

I think i've got it, but its too late to run it tonight. I still don't entirely understand it, but what I'm assuming was the PTO safety had failed, had become disconnected or both. The part that puzzels me is that it was causing the lights not to come on too. I put my meter on it with the tone, and I couldn't get the tone to stay on consistently at all. I took a two inch piece of heavy guage wire, gave it a good whack with a hammer to flatten the ends, bypassed the safety, and on came the lights, and she cranks.

 

[rwall10597]

And no... I had put the battery charger on it for a little bit here and decided I should bring the charger in for the night. I figured heck, I can run it for 2 minutes to put it by the street, and once again, no lights, no crank, and the fuse is blown.

Back to square one, but we can probably rule out the PTO safety. Thoughts...

 

[rwall10597]

If anybody has a wiring diagram they could send me a link to that would be great. Its model 31-17KE01, 1985.

 

[monteman_73]

Wow, sounds like you have a real head ache here. I worked on a car one time that would randomly blow a fuse. When it blew, it blew good. What I ended up doing was installing a 10 amp fuse on every wire that was connected on that one circiut, then I installed the correct fuse in the fuse box and let the customer drive the car for a couple of weeks or until they notice something not working. It made it a little over a week and one of the 10 amp fuses was blown. I followed the wire and it was going around a piece of metal that had a sharp edge under the dash. So my suggestion would be to follow the main wire from the blown fuse, and install a 10 amp fuse on each wire that branches off from the main wire. This way when a 10 amp fuse blows, you'll know which branch of the circiut to check out. And if the 30 amp fuse blows again, then you know it is from the 30 amp fuse to the 10 amp fuses. Good luck in your venture.

PS, the 10 amp fuses can be the "spade" type fuses if you want. They may be cheaper than the glass fuses. (I'm guessing it's a glass fuse.)

 

[gwest_ca]

No 1985 wiring but the 1986 is in the Files of
http://groups.yahoo.com/group/wheelhorsetractormanuals2_86a/
named
Tractor 1986 400-Series OM #810399R1.pdf
and
Tractor 1986 400-Series OM #810437R1.pdf
Two different versions of the operator manual and they have the wiring diagram.

Garry

 

[rwall10597]

Gary, I played with it some over the weekend but didn't have a ton of time. I didn't do exactly what you said yet, but that is my next step. I may need to pick your brain some more, more so with the basic principles of it, I'm embarrassed to say i had a tough time getting my head around it. My multimeter has a setting where it sounds a tone when you have a connection, I was using that like it were a test light, and that kinda messed me up. I believe I've got my head around it now, but by the time I did I was out of time to work on it.

I've got the schematic toro website for order electrical parts. Its a good checklist if nothing else.

One question, the PTO safety switch. I have bypassed that. That is just supposed to make a hard connection between the two wires right? That was completely rotten and I'm not sure how it was letting the tractor run as long as it did.

I had hoped it was the ignition switch grounding out to the housing, it was a mess when I pulled it off, but I cleaned it up with a wire brush and tested it and it worked fine, same with the headlight switch.

I'm able to crank if I jump straight off the bottom of the solenoid, and the headlights work if I jump straight to the switch, so that leaves me with a bare wire somewhere in the harness or the voltmeter or hours meter grounding out.

Thinking back the last several months, I would turn the key to start lets say 3 times and nary a click, then the 4th time it would start like a new machine. Does that seem like it would be a failing solenoid? And do you think its possible for a failed solenoid to cause a hard short like this?

 

[rwall10597]

I believe I have it narrowed to the stator and/or the rectifier. My meter could be better, but the best I can tell the stator is grounding out. I also can't seem to get proper readings on the rectifier either. With the rectifier unplugged, I'm able to turn the lights on and crank the starter without blowing a fuse, so I know I'm close.

I pulled the housing off and, I'll get a loaner fly wheel puller tomorrow, I'm guessing I'll find the stator is toasted. That horizontal twin sure makes it easy.

A few question for you folks, what's my best bet for getting a new stator and rectifier? Should a decent lawnmower shop stock them? Are they generic enought that an Autozone or similar might carry them?

Also, to test these two things, what setting do I put the multimeter on and what readings am I looking for? I was using Ohms for both. I'm getting virtually zero Ohms across the stator, and honestly, the rectifier has me confused, I'm thinking the lag on my digital meter might render it useless for this. Anybody have any tips?

 

[monteman_73]

Without a manual to look at, it's hard to say what is right and wrong. If I remember right, when I used to rebuild alternators on cars/trucks, the stator would have practically 0 ohms. But to check diodes/rectifiers, your digital meter HAS to have a diode mode. The old analog meters didn't need this mode because it put out enough "amperage" to test diodes/rectifiers. Digital meters are computor safe, but they don't have enough "amperage" to test diodes/rectifiers. That is why they put the diode mode on the digital meters. (Not all digital meters have this selection.) Before you start replacing stuff, with the rectifier unplugged, start the engine and check what kind of A/C voltage you get from the stator. If it is in the mid 20's to the low 30's, I'd say the stator is fine. Here is where some people get confused about a stator. A stator doesn't RECEIVE battery power, it makes power. I've never seen a shorted stator blow a fuse, (Not yet anyways.) it simply would not charge. Now a bad diode or rectifier CAN send battery voltage to a GOOD stator, (Which it ISN'T supposed to do.) and blow a fuse. If you find your stator to be good, can you plug in the rectifier and NOT have the stator wire(s) plugged in? If so, check to see if there is battery voltage trying to go to the stator. If there is, I'd replace the rectifier. Good luck in your venture.

 

[rwall10597]

Very helpful thank you! Signs are pointing to the rectifier aren't they. I think I'm going to pull the stator off anyway to inspect it, it's jammed full of crud so so I at least want to clean it up. When its unplugged, I shouldn't get any connectivity between either side of the stator and ground right? I may have been.

 

[rwall10597]

I've ordered a new rectifier, $27 shipped, seeing as how the tractor is a 1985, even if the new one only lasts half as long I think I'll be OK. I borrowed a puller to remove the flywheel and clean and inspect the stator, hopefully I'll be back up within the week.

 

[monteman_73]

When its unplugged, I shouldn't get any connectivity between either side of the stator and ground right? I may have been.

I'm not positive on this since I don't have a manual on the stator. I'm thinking that it may have continuity to ground because if the 2 stator wires are going to the rectifier, there has to be a ground somewhere to "push" the voltage. I'd almost bet that both stator wires are pulsing the opposite current of each other, if they weren't, then you would only need one stator wire because the other end would be grounded at the stator. But since the stator wires are pulsating the opposite current of each other, (Which I believe is the case, someone correct me if I'm wrong.) there is a constant charge going to the battery this way. Because a stator with a built in diode only charges half the time.

 

[rwall10597]

alright, I've got the stator at my desk, it was jam packed with 26+ years of dirt, I've got it all brushed. I've got one of the 18 posts (if thats what they are called) has about half the black off the copper, and I can see a chip out of the wire, something must have gotten tossed through there at some point, could have been the size of a large piece of sand, I'm kinda guessing it grounded for a second, but who knows. My hunch is that its gots some hours left in it though so I'm going to roll with it for now.

I've got the flywheel sitting on my bench. I'm concerned because one of the six magnents was stuck to the stator when I removed the flywheel, one more was loose and came off while I was cleaning the dirt out.

Is there any way of reattaching them or is the flywheel shot? Grollia glue, JB Weld?

 

[rwall10597]

So I'm back to thinking the stator is toasted. I have continuity from left to ground, right to ground and left to right... I'm thinking thats a shorted stator...

 

[rwall10597]

I decided to give the JB Weld a 'whirl' seeing as how its on a flywheel. I clamped it overnight and it seems to be rock solid, put it back on and ran the tractor back up into shed and it worked just fine. Hopefully next weekend I'll have the parts to put the charging system back together.

 

[rwall10597]

Given whats available on E-Bay for used stators, would you recommend going new, or would a used one be fine? I don't know what the life span of a stator is. One thought is that as long as its kept clean it won't short out, which is what I'm guessing happened to my old one, on the other hand, the used ones I see are from the late 70s.... and that's getting kind of old.

 

[rwall10597]

New stator, new rectifier, new battery, like a new machine. The voltage is better with the lights on then it ever was with the lights off in the 5 years I've had the machine. Overall, very easy job once I figured out what the issue was. I'm embarrassed because for years I've been the one telling people, its just the battery, but I was convinced my starter was going too, but there was almost nothing left of the battery. Replaced the battery and it cranks like a new machine. Thanks all for the diagnostic help.