Blown fuse maybe, you still could have a bad safety switch too.

Dont think I have any more safety switches to check and I looked at the fuse and it looks good.

Check the circuits with a volt ohm meter. Some times you can not visually tell if a fuse, or fuseabe link is good

Well, this depends on what you call the primary terminal of the solenoid. The small terminals: One line is the safety line and needs a ground present to crank. The other is triggered by 12 volts. What is missing?

The flat terminal where the wire can be pulled off, not the upper posts that have wires nut'd down to them, is the one I saw referred to as the primary terminal and is the one I attached the lead wire to, with the other end of the lead wire going to the positive terminal of the battery, and doing this attachment caused the engine to turn over. So I'm still wondering if this rules out the solenoid being bad?

Posting the sears 917.xxxxxx number would allow one to look at the correct electrical schematic.

Your solenoid is good.

You didn't state if the tractor makes any clicks or is dead silent when you hit start.

Assuming you have a carburetor fuel solenoid, it should click each time you turn the key ON/OFF. If it doesn't, check the fuse.

I'm not getting a clicking noise when turning the key though I used my multimeter to check the fuse and it was good. Just before this no-crank situation happened, I had the mower parked on an incline for a week or so, then after about a minute after running the mower lots of white smoke came from the mower, presumably burning oil due to being on the incline. I ran it for a minute or so while it was smoking. I wonder if the heat buildup did something to the wiring? This Craftsman riding mower was built in 2004 and the model # is 536.27029

there are a couple of murray wiring diagrams here. Go down a few pages to find the diagrams.

http://www4.briggsandstratton.com/miscpdfs/RNT/Murray%20Electrical%20from%20MA-S-1612%202004%20Quick%20Reference.pdf

Your test on the starter solenoid indicated this was good. Your test on the fuel anti after fire solenoid indicated either this item was bad - or it was not receiving power. Follow each component on the diagram starting from the battery. Examine wire terminals for corrosion. Test the key switch and each safety switch.

You can get the actual schematic from Sears here-

http://www.searspartsdirect.com/model-number/536270290/0247/1506000.html?searchType=modelSearch&q=536.27029&searchTerm=536.27029

Trace the S terminal of the key switch to the solenoid.

Based on what I've already described, is it possible the ignition coil is bad? Also, I noticed the electric wiring diagram shows a "test port". I see the test port on the mower but I haven't found any information about it on the internet. I was wondering if there was a way, assuming wiring is the problem, to do some kind of diagnostic through the test port without having to uncover all the wires?

do not connect any power source to the test lead. This is part of the ground circuit. You previously stated the engine started when you energized the starter relay. This indicates the ignition coil is working.

Bill provided the correct electrical diagram. Use your ohm meter to check the continuity of the orange wire from the starter relay to the starter switch. During this test the pto should be off and the brake pedal up. If you have continuity, the starter switch may be bad or the hot (power wire) to the starter switch does not have power.

If there is no continuity, test continuity through the pto sw and then test continuity through the pedal switch. If this test indicates continuity, look for corroded wire terminal or a broken wire.

Great info bluemower! Thanks so much. I hope to get back out looking at the mower sometime later this week to try and solve the problem.

I am surprised no one caught my error. My eyes are worn out and I was looking at the wrong circuit through the pedal switch. Here is the correct comment.

" During this test the pto should be off and the brake pedal down."

I actually wondered about that too, thinking the pedal should be down. Thanks for the correction.

OK I checked continuity on all the wiring and it all seemed good. Then I did a test I found on the internet where you place one prong of the multimeter on the ignition (orange) wire after disconnecting it from the solenoid spade terminal, the other prong grounded to the frame, then turn the ignition key. When I did this several times I got between 10 and 11 volts each time. Then I reconnected that wire and placed the prong of the multimeter on the upper right post of the solenoid, the post that has the wire going to the starter, with still the other prong grounded to the frame, turned the key and the multimeter showed no volts. If the solenoid was good, shouldn't I be getting 10-11 volts from that test too? I realize I should be getting 12 volts but wouldn't 10 volts at least crank the engine attempting to start? I know my earlier test where I hooked a wire between the battery and the ignition terminal of the solenoid indicated the solenoid was good because it caused the engine to crank but now I'm not so sure the solenoid is good.

1. TEST battery voltage to make sure it's 12+V. Less than 12V and it's severely discharged.

You have high resistance somewhere between the Key Switch and Solenoid.

Digital test meters draw so little current that you can pass enough current to operate the meter, but little else. (measure a penlight battery and see how close to 1.50VDC the meter reads to get an idea of its accuracy)

Perform the identical test where you got 12?V, subbing a 12V test light. IF you have good connections, it'll light. If not, it won't.

Look at post 9 in this thread-

http://www.mytractorforum.com/16-simplicity-allis-chalmers-forum/1147282-simplicity-sunstar-20hp-electrical.html

Well, I broke down and put on a new solenoid despite doing the jumper test that seemed to rule it out being bad, and lo and behold, the mower cranked. However it did not start. I hope this is just a case of a carboratur needing some cleaning, though the cranking noise sounds a little different than before almost like a grinding noise. I hope to report back tomorrow with a running mower.

Well it's nearly a month later and I still don't have my mower running. After cleaning the carb the engine was back to not even cranking. I made sure the battery was fully charged. I put in yet another solenoid. It still didn't crank. I bought a new starter and it still doesn't crank. When i take a screwdriver and touch both terminals of the solenoid nothing happens. When i take a jumper cable and attach one end to the positive terminal of the battery and the other end to the starter it sparks and heats up a lot but usually doesnt even turn the starter. I have the key to the on position. When it did turn it was very weak and not a full crank. One thing I don't understand is why, when I'm back to using the ignition switch to start it, I don't get any volts coming off of the starter wire side of the solenoid if the solenoid is working? I'm getting the full 12 volts from the ignition wire. I keep thinking something is messing up the solenoid and I've put three new ones in there now. but even bypassing the solenoid like i did still didn't crank the engine. The battery is fully charged the multimeter reading 12.7 volts. I've spent way too much time on this mower to still not have it running. Any idea what could be going on?

Did you ever find the problem