Mower won't turn over

[excalibur2]

Hello all, Jim from CT here. Been banging my head against the wall for weeks now trying to get this mower to turn over. It is a craftsman model 536.270320 mid engine rider. Turn the key to starting position and nothing happens, not even a click. Installed new solenoid, swapped out starter from another rider which I know is good, replaced safety switch under the seat, checked entire wire harness and no cuts or breaks, tested both pto safety switch and the brake safety switch with an ohm meter, both have continuity. I don't know anything else I could check. Also put new fuse in as well as another ignition switch. What's left??? Is this solenoid wired correctly? Can the black wire from the harness share the same ground as the neg battery terminal as shown below? Red wire on right goes to starter, red wire on left goes to pos battery terminal.

 

[bertsmobile1]

Start from the top.
1) check that the engine actually rotates by rotating it by hand.
2) Measure the voltage between the battery terminal on the solenoid and the ground.
If you ain't got 12 V here you ain't got nothing.
3) Bridge the two terminals on the top of the solenoid.
Starter dosn't turn then the battery or the battery terminals are suspect.
4) run jumpers from the battery directly to the starter terminal on the solenoid
Engine should crank, if not the ground cable is bad.

Try a known good battery.


It matters not where the ground terminal attaches to.
However as the starter motor is the heaviest current draw, I always reroute it to one of the starter motor mounting bolts even if that means runinng a new ground or secondary ground.


Finally

THE SEAT SWITCH HAS ABSOLUTELY NOTHING TO DO WITH THE ENGINE STARTING SO LEAVE IT BLOODY WELL ALONE

 

[mechanic mark]

http://www.searspartsdirect.com/mod...=modelSearch&q=536270320&searchTerm=536270320

wiring looks good, remove battery & take to local auto parts store for load test, should be of no cost to you

check spark plug wire for being loose on plug or disconnected

 

[excalibur2]

Battery is good, reading 12.7 volts. Jump from solenoid to starter will turn the starter. Also tried a second battery that I know is good and still nothing. Engine rotates by hand just fine. This happenned all of a sudden. It was being used and was running, turned off for 20 min to eat lunch and came back and everything dead.

 

[excalibur2]

"2) Measure the voltage between the battery terminal on the solenoid and the ground."

...so just take red probe on my multimeter and touch the pos terminal on the solenoid, and touch the black probe to the ground screw in the frame?

 

[bertsmobile1]

Yes, but if the starter works when you bridge the two terminals on the solenoid one can safely assume you have a good connection to the solenoid.

So the wire from the hot terminal to the ignition switch will now be the prime suspect.
It should have a fuse in it.
Check for voltage at both side of the fuse holder then at the B terminal on the ignition switch.

 

[excalibur2]

Fuse is good, tried about 5 brand new one's just to be sure. How would I check voltage at fuse holder or B terminal at ignition switch? Red probe to B and black probe to G? Do I need to have parking brake on and key turned all the way to start position at the same time?

 

[excalibur2]

BTW , red probe to positive terminal on solenoid and black probe to ground reads 12.74 V.

 

[bertsmobile1]

Fuse is good, tried about 5 brand new one's just to be sure. How would I check voltage at fuse holder or B terminal at ignition switch? Red probe to B and black probe to G? Do I need to have parking brake on and key turned all the way to start position at the same time?

Basic mower wiring
Battery- solenoid terminal-fuse- B terminal ignition switch - S terminal ignition switch - Pto switch - parking brake switch - trigger terminal on solenoid- ground
Somewhere in that chain above is a broken link.
I like to use a test lamp that has a clip on one end so I have a spare hand to pull wires & work switches.

 

[excalibur2]

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