Mower won't turn over

[bertsmobile1]

ok, I'm getting 12.74 volts at the fuse terminal, now what?

So carry on along the chain,
Ceeck the output side of the fuse then the B terminal on the ignition switch, the S terminal etc etc.
Somewhere between the red wire and the orange wire there is a break in the wiring,

 

[excalibur2]

somewhere along the lines testing all this stuff i managed to blow the fuse.{just noticed} Put a new one in and still dead. All wiring looks like new, I peeled quite a bit of the wiring from the corrugated jacket from the brake switch end all the way up to the solenoid end. I don't see any breaks or cuts anywhere

 

[bertsmobile1]

Seeing is not testing.
Every wire in the cranking circuit.
Both sides of every switch
One of them is bad.
Be methodical
Input side & output side
Switch open & switch closed.

We has someone here a while back that he had ants in his PTO switch which caused random no starts when they got stuck under the sliding blade on the switch.

I know it is a PIA, my backside stings regularly trying to sort these things out.

Fairies & gremlins do not exist, electron do
And some where between the terminal on the red wire and the terminal on the orange wire there is a hole and the smoke is getting out.

 

[excalibur2]

I do appreciate all the help, but my knowledge of electrical testing only goes so far. Can a switch be bad even though the continuity tests good? Could the kill wire have anything to do with a no crank situation? this is driving me nuts. Trying to help out a friend { it actually belongs to him}, I'd hate to tell him I can't fix it, and at this point it's become a personal obsession lol.

 

[bertsmobile1]

I do appreciate all the help, but my knowledge of electrical testing only goes so far. Can a switch be bad even though the continuity tests good? Could the kill wire have anything to do with a no crank situation? this is driving me nuts. Trying to help out a friend { it actually belongs to him}, I'd hate to tell him I can't fix it, and at this point it's become a personal obsession lol.

No the kill wire has nothing to do with the cranking circuit.
I have already told you what the circuit is.
Continuity testing sort of works but a test lamp works better.
Poke the probe up the bum of the plugs to get contact with the wire.
It is really not hard, just follow the wire from one end to the other,
Tedious, yes
Frustrating yes
hard no

 

[excalibur2]

I have a test lamp and aside from touching the probe to battery side of solenoid post and ground clip to ground screw and getting the beep and the light, I'm really not sure how to use this tool to continue the entire circuit test for voltage { touch probe to where, negative clip to where, does key have to be turned all the way, does brake need to be on, does operator need to be on the seat, etc, etc. I did use another tool I have to test voltage in the fuse socket { multimeter } which read 12.7. The continuity tests I tend to understand a bit better - one probe to one end of anything metal and the other probe to the other end. If it reads zero's or anything ever so slightly above, it's good and will complete a circuit. Now as far as voltage testing I'm just not that experienced.

 

[bertsmobile1]

Exactly the same way.
Leave the clip connected to a good ground.
Anything you touch with the probe that is live will make it glow & beep ( you have a good one ).
So you start the probe at the solenoid terminal then go up the red wire and push the probe into the back of each side of the fuse holder.
Again it should beep.
Follow that wire up to the ignition switch and poke the probe into the back of every wire in the terminal block.
With the ignition off only one wire should beep ( the one from the fuse ).
Get a strong magnifier and look at the back of the old switch.You should see tiny letters
G = ground
M = Magneto
B = Battery ( should be connected to the fuse )
S = Start
A = Alternator
L = Lights ( fuel solenoid is generally connected to here )

Some will have 2 L and or 2 A terminals

Now back to the mower.
All you are interested in right now is the cranking circuit so push your probe into the back of the S terminal while holding the key in the start position.
You can do it to all the terminals in the off, on and start for the heck of it if that will make the actions of the switch clearer.
Follow the wire from the S terminal to its next switch, should be the PTO ( Switch if electric PTO , safety switch if a lever PTO ).
Here you will need 3 hands because you need to test the wires with the ignition in the start position and the PTO both on and off.
You will find it easier if you pull the plug on the ignition switch off and poke a short jumper between the B & S wires on the plug.
IF the pto switch passes power through it in the off position, follow the wire , It should now go to the parking brake.
Same proceedure.
Mechanical gear box mowers will also have a reverse safety switch in the cranking circuit, hydros don't.
Eventually the wire will come back to the solenoid.
Some of the safety switches will have 4 or even 6 wires , 2 will be coloured and the rest will be black, brown or white with or without a stripe.
All the similar wires will be part of the magneto cut out and are not part of this test ( they will either be ground or open )
On some mowers the wire changes colour every time it goes through a switch while others it will be the same colour from the S terminal on the ignition switch all the way through ( usually yellow or orange )
Keep a note pad with you and write down the colours as well as weather it was live ( beep & lights ) when the switch was on or off.

If a wire is broken where the terminal crimps on and you poke your probe into the back of the plug, it might cause the broken wire to make contact which will crank the engine if you have jumped the plug on the back of the ignition switch,
Be ready for it as it can suprise you and do not put anything on top of the engine nor lean on it.

Somewhere from the red wire on top of the starter solenoid to the orange wire which triggers the starter solenoid there is a broken connection.
Double check that the orange wire does not have 12V on it when you turn the key to the start position.
If the orange wire goes live when you turn the key the solenoid is the problem.

 

[excalibur2]

Ok that makes more sense to me, I will lick this issue yet. One thing though:

" check that the orange wire does not have 12V on it when you turn the key to the start position.
If the orange wire goes live when you turn the key the solenoid is the problem."

I thought that if i connect my neg clip from test light and touch the probe on the small spade terminal on the base of the solenoid { orange wire}, I am supposed to get 12v. Isn't that orange wire the same wire that sends a signal from the ignition switch to tell the solenoid to do it's job and crank the starter??

 

[bertsmobile1]

Sorry, badly written.
With a known good fuse in the red wire, check the orange wire for 12V when the ignition switch turned to start.
Yes you are correct it is the orange wire that makes the solenoid switch the juice to the starter motor.
So we should check that before you go digging through the rest of the wiring to confirm there is a problem with that circuit.
When I re read the the whole post I noticed I had assumed the orange wire was at fault but we had never actually checked it.

 

[excalibur2]

Ok here's the latest: Will check orange wire soon as I get a second person, seems I need 6 arms for this test! Anyway, for 16.00 i purchased the 2 switches today. PTO switch and brake/clutch switch. Still nothing, completely dead. Removed entire harness from tractor, went over every inch of every wire with a magnifying glass, no cuts or breaks. Tested continuity from one end to the other on every wire, every lug and hole, all tested 00000 or very slightly above. Just curious, I am wondering if there is an engine ground wire hidden somewhere? At least I can rule out all switches { except reverse safety switch which even if bad would still allow engine to crank providing blades are not engaged}, so in a nutshell it must be something much simpler, especially when the mower was running one minute and ten minutes later she went completely dead.