Need Help with troubleshooting ignition switch on Murray 12.5 HP

[EngineMan]

Did you do what I said to do in post #6 if you do that, we can come away from it knowing it works.....with me...?

 

[EngineMan]

I secured the loose ground wire to the solenoid frame. Still will not start.

Also still No Voltage on small solenoid hot lead when measured while turning key to START.







I do have 12V at pin to, so on to safety switches. I wonder if the ground coming loose caused failure of one of the safety switches. Seems unlikely to have them both go out at same time.

Any suggestions on how to test the switches, assuming I can reasonably access them?

I think at some point someone had renewed the sloenoid and forgot to refit the ground lead.
the way to test safety switch, there will be a Orange wire going in, and a Orange wire coming out, set meter to Ohm's and connect leads to both wire's you should have continuity when you push or release the switch.

 

[EngineMan]

Do you have power coming from Pin 5 ignition switch when you turn the key to start..? very important. Man am working hard here...!
And where is Rivets when I need him...!:wink:

 

[MTD]

Did you do what I said to do in post #6 if you do that, we can come away from it knowing it works.....with me...?

Ok. Did as advised and it turns over.

I think at some point someone had renewed the sloenoid and forgot to refit the ground lead.
the way to test safety switch, there will be a Orange wire going in, and a Orange wire coming out, set meter to Ohm's and connect leads to both wire's you should have continuity when you push or release the switch.

I can access ORG wire on switch harness but other ends will be tricky. So far I can only find the blade/deck switch, which I think is marked PTO on schematic.

 

[EngineMan]

Ok so we know now that the solenoid will work when it gets power, so now take you're time and check wire and safety switch(s) do a continuity test at Orange wire on safety switch one of them will have continuity back to the end of the orange wire that fits on solenoid, and keep checking on each switch, make sure you have power from Pin 5 when you turn the key to start, if you don't have power there its the switch you need to renew.
Not sure how long you are going to work on this today, but let me know, so I can come away from the post.

 

[MTD]

Ok so we know now that the solenoid will work when it gets power, so now take you're time and check wire and safety switch(s) do a continuity test at Orange wire on safety switch one of them will have continuity back to the end of the orange wire that fits on solenoid, and keep checking on each switch, make sure you have power from Pin 5 when you turn the key to start, if you don't have power there its the switch you need to renew.
Not sure how long you are going to work on this today, but let me know, so I can come away from the post.

I located safety switches and will try a continuity check. I'm not sure there is a way to verify power on pin 5 when key is turned to start. The harness must be plugged in to back of switch so there's no access to that wire. I still suspect the possibility of a faulty ignition switch. I'm going to have to call it a day for today but should return tomorrow first thing. Thanks again EngineMan for your help so far.

 

[EngineMan]

Should'nt need to have harness plugged in you can do a continuity test just with the key switch across 2 and 5. with switch in start.
Its always best to go over things slowly so take you're time, I'll be around tomorrow.

 

[MTD]

make sure you have power from Pin 5 when you turn the key to start, if you don't have power there its the switch you need to renew.

If I am following you, there is not. I'm basing this on the fact that I removed the small orange wire from the solenoid and measured voltage there while turning the key to START and got no voltage.

I have removed the old switch and strangely enough I get good continuity from pin 2 (hot from battery) and pin 5 (solenoid) when key is turned to START. However, the connection between pin 4 (M) and pin 6 (Ground) in the OFF position is very dodgy - sometimes it will read a few ohms, then jump to MegaOhm readings and is sensitive to key jostling. I know this is for STOP but could this prevent start as well?

 

[EngineMan]

Pin 4 is the kill wire, I think you may need a new ignition switch. to start of with.

 

[MTD]

I just picked up a new switch and will say more about that in a moment.

I just completed a check of the safety switch ORG path.

Brake Switch: checks GOOD

Path from Solenoid wire (org) on switch harness to Brake Sw: GOOD

Path from small org solenoid wire to brake sw (via the PTO/blade sw): GOOD. I did this by simply lowering the deck so switch and connection look ok.

Yellow Wire Path:

From Magneto wire (two Yel) on back of key switch harness to Ground shows continuity in BOTH seat positions. I may not be understanding the schematic but shouldn't the ground connection on this leg open when the seat switch is pressed ( sitting on the seat) ?

I still need to pull the switch out and test the positions which I will now do.