L4610 zero electric power and I'm stumped

[Crabapple Pete]

Our L4610 hardly gives me any trouble for what I do with it, but this one has me scratching my head- the other day I was running it in the yard doing light duty work, pulled it into the shed afterwards & shut it off, everything seemed normal. About an hour later I went to start it up, and *nothing*- no lights, no dashboard indicators, so sound from any of the relays, no cranking, no nothing. She acted absolutely totally completely dead.

Got my multimeter out, found 12.7 volts at the battery. Figuring I have a loose wire, I started tracing my way back from the battery. Found 12.7 volts at the stud under the starter (where the battery cable comes back), same at the alternator. Found 12.7 volts coming into the key switch; nothing going out with the key off, but yes 12.7 volts at both switched terminals when I turned the key to "on". Then got 12.7 volts at the last terminal on the back of the key switch when I held the key in the "start" position. I have 12.7 volts coming into the light switches, but again no lights.

Now thinking I have a bad ground wire, I checked for continuity from the negative battery terminal (terminal, not clamp) to the tractor frame and lo everything seems ok there as well.

I then turned the key on and turned every accessory on to look for a short, but nothing changed and after 3 hours of poking around & increasing language I still had 12.7 volts at the battery so nothing was pulling it down. This one really has me stumped, any ideas what I'm missing here?
-Pete

 

[TheOldHokie]

Our L4610 hardly gives me any trouble for what I do with it, but this one has me scratching my head- the other day I was running it in the yard doing light duty work, pulled it into the shed afterwards & shut it off, everything seemed normal. About an hour later I went to start it up, and *nothing*- no lights, no dashboard indicators, so sound from any of the relays, no cranking, no nothing. She acted absolutely totally completely dead.

Got my multimeter out, found 12.7 volts at the battery. Figuring I have a loose wire, I started tracing my way back from the battery. Found 12.7 volts at the stud under the starter (where the battery cable comes back), same at the alternator. Found 12.7 volts coming into the key switch; nothing going out with the key off, but yes 12.7 volts at both switched terminals when I turned the key to "on". Then got 12.7 volts at the last terminal on the back of the key switch when I held the key in the "start" position. I have 12.7 volts coming into the light switches, but again no lights.

Now thinking I have a bad ground wire, I checked for continuity from the negative battery terminal (terminal, not clamp) to the tractor frame and lo everything seems ok there as well.

I then turned the key on and turned every accessory on to look for a short, but nothing changed and after 3 hours of poking around & increasing language I still had 12.7 volts at the battery so nothing was pulling it down. This one really has me stumped, any ideas what I'm missing here?
-Pete

Try using a 12v incandescent test light instead of that VOM. I bet you get a differrent indication.

Dan

 

[GreensvilleJay]

If ,when you measured those 12.7 reading,s the negative of the DVM was on the negative battery post, then you have a bad ground

BTW a 'short' is usually seen as a blown fuse, an 'open' will be seen as 'no voltage'.
If you can ,post the wiring diagram.

 

[Crabapple Pete]

If ,when you measured those 12.7 reading,s the negative of the DVM was on the negative battery post, then you have a bad ground

BTW a 'short' is usually seen as a blown fuse, an 'open' will be seen as 'no voltage'.
If you can ,post the wiring diagram.

Yup dummy me that was it- I had clipped the negative lead on my tester to the bolt where the battery cable attaches to the frame. When I moved to a different place on the frame, poof no ground. I took the negative cable off both ends, cleaned the connections all around, and she came back to life. Thank you!

 

[Mark_BX25D]

BTW a 'short' is usually seen as a blown fuse,

No, no, no. That's not right! A "short" is any electrical problem that is not understood!

Vehicle won't start? Must be a short!

Lights won't come on? Must be a short!

Blinker is intermittent? Must be a short!

Stereo is too loud? Must be a short!

 

[lugbolt]

forget a continuity test. A continuity test tells you the resistance of a conductor

one strand of a conductor can conduct electricity but it won't conduct enough electricity under a load in a lot of cases

thus, a voltage drop test. Saves your tail end in diagnosis once you figure out how it works

basically you take your dvom and put one probe on the positive terminal of the battery, and the other on the items that might be suspect causing the issue. Let's say we think the battery cable is suspect. One probe of the dvom on the positive battery post and the other end on the starter. Hit the key. What's the dvom say? If it says 500mv or less, that's good. If it says 12.23v, that means there is a 12.23v drop between teh battery and the starter, meaning you're losing 12.23v somehow. That could be a connection at the battery cable, or the cable itself failing internally

or another way to test. Put the dvom on the battery terminal and the other probe in a connector, where a positive wire would go through (not a ground). Load the circuit (lights, whatever). Read your dvom. If it's 500mv or less, that's fine the circuit is ok. If more, and usually when it won't start or a component don't work, you'll see a lot more...6v+ normally.

Same deal you can also test it on the ground side and all of the ground circuit connections and conductors.

again once you figure out how to use this test you will use it a lot more. Techs? If u don't know how, this post tells you how and once you master it, it'll save you (and your customers) a LOT of time and money.

My boss has a L4600 had similar symptom. Him and I hauled all the way to where the tractor was at. he messed with it all weekend trying to figure it out. With my dvom, I had it figured out in under a minute. Failed slow-blow fuse, the fuse itself wasn't "blown" rather it's holder was corroded up and not making contact. Mind you my boss is pretty sharp mechanically...