Small Engines (Lawn Mowers, etc.): 12 HP 40 Murray Riding Tractor, amp fuse, voltimeter

Question
I have recently acquired this lawn tractor that I knew wasnt running.  My dilemma is no power at all.  It will not even try to crank over.  I put a new fully charged battery in it, and still nothing.  I replaced the solenoid, still nothing.  It is a model  40603A, which I was able to find the wiring schematic online for.  I know that the previous owner "tinkered" with it, and I am not sure if it was wired correctly to the solenoid--& battery. (I just copied the existing wiring)  My voltimeter (?)  on the dash reads 0 with the new battery.  As I said earlier I found the correct wiring schematic online @ http://partsandservice.com/html/Murray/lt/lt40603a.html
But it is not clear where/which wires connect to the solenoid.  Are you familiar with these kinds of wiring problems? Could you confirm what I have figured out so far and take me the rest of the way?  I believe the Negative Black from the battery and the yellow from the seat safety switch mount to the chassis. Im not sure where the other 4 wires--Positive (red) from the battery, The (red) from the 15 amp fuse, the red from the engine and that black wire connect to the solenoid.  And while I have your attention, how the heck do you test +/- bypass the safety switches?  Perhaps  I may also have to change out the ignition switch down the line. Is there anything else I may have looked over? Thank you very much for any assistance you can give.

Answer
Hi Audrey,

Sorry for the delay.

It sounds like you might have read my No Crank proceedure but if not, I have added it below.  

The red battery lead goes to the large terminal on the solenoid.  A wire, usually red from the keyswitch goes to the small terminal on the solenoid.  A black wire may go to a ground terminal.  

If a safety switch is normally open, for the engine to run, you can disconnect one lead to bypass it.  If the switch is normmally closed, you would need to connect each terminal together with a double ended allegator lead or other wire.

Let me know how you make out.
Michael


I would check the starter first.  Jump the positive battery terminal to the starter and it should crank over. If so, skip to step 2.
If not, jump from a battery that you know is good, from a car.  If still nothing, the starter is bad.  If good, then the mower battery is weak.  

Step 2.
If the starter and battery are good, you will need to trace the entire circuit from the starter to the battery.   The solenoid, switches the battery power to the starter, when power from the key switch is sent to the small terminal on the solenoid. To test the solenoid, first make sure that you have power at its large terminal which comes from the battery. Then jump power from that terminal or the battery positive post, to its small terminal. You should hear a click and the other large terminal that feeds the starter should be energized. If not, then the solenoid is bad. If good, then continue tracing the power through the key switch to the battery until you find the break in the power path.   All testing can be done with a 12 volt light or a voltmeter.  Most equipment has safety switches in  the seat and on the blade engagement lever. Check them by temporarily bypassing with a small jumper wire.