MTD LT12..38 tractor...this is a tough one!

[KE4AVB]

Brian, I have seen Black to use as the positive power lead. What some manufactures are doing is using the color code household wiring. Where black is usually the 120 vac hot lead and white the neutral and green the safety ground. Here on this MTD balck is carrying 12 + vdc and they are green for the magneto ground circuit along with the headlamps ground return circuit.

I just wish they would use DC electrical wiring color coding where Red is + DC voltage and Black is the - DC return line.

[bgsengine]

I just wish they would use DC electrical wiring color coding where Red is + DC voltage and Black is the - DC return line.

I wish they'd standardize color coding, period.. so wire colors would tend to mean the same circuit across all machines from the same manufacturer... but that'll never happen.

I've seen too many generic diagrams that were off base from the original wiring, to ever really trust the diagrams from ARI images (if you notice the watermark of the image..) If the wiring colors matched exactly on the machine and the diagram, then I'd believe the diagram...but too often I've tried to trace a circuit by a diagram's wire color code only to discover (after giving up and cutting the harness out of the conduit and tape) that the diagram was wrong... so I rarely put all my faith into a diagram like that - but in the diagram above, as I had noted, green has nothing to do with his start circuit at that point - solenoid appears to be a 3-post so it grounds through the base.. so I was trying to direct him away from chasing that green wire, it should have no relevance to start circuit, nor should that wire (that grounds to the solenoid) have any relevance to the magneto circuit either..

(magneto ground should go to the key switch M terminal and only connect to ground when switch is off, and should have 0 volts..... back where he said he had 12v at the green wire at solenoid, I would expect it to be 12v if it was not fastened down, and key on, since it is the ground for headlights and would be showing 12v if it wasn't contacting ground, and headlights on.. and should not have anything to do at all with the magneto circuit)

[dart451]

No, I corrected myself...the green wire did NOT have power, I thought I was touching the green wire on the ignition plug but I was touching the black. So, I traced power to the orange wire at the PTO(I think)...that's about as far as I got. I can't check power from the other side inside the tractor...

[KE4AVB]

I can't check power from the other side inside the tractor...

Now that what I use trained mice for.

But seriously be careful reach up inside machines or you be like me where I wet my shorts when I grabbed a snake. Lucky that it wasn't poisonous but still scared the P out of me.

[dart451]

What's strange is...it appears that the orange wire first goes to the clutch and then the PTO but it looks like it goes from the switch, to the PTO and then the Clutch...(scratch my head)

[38racing]

What's strange is...it appears that the orange wire first goes to the clutch and then the PTO but it looks like it goes from the switch, to the PTO and then the Clutch...(scratch my head)

Not sure what you are saying. From the schematic that you posted orange goes from keyswitch to clutch switch to pto switch to small terminal on solenoid. It doesn't real matter if it goes to pto and then clutch. It's a series circuit. Both pto and clutch switches must be closed to get engine starter to crank.

[dart451]

Ok, then it doesn't matter which one it goes to first...I'll check it out tomorrow morning...

[dart451]

So, I have noticed, more so recently, that if I can't figure out something right away I want to abort the fix! I always come to THIS forum and you guys always get me through this! Perhaps I'm getting to old to mess with this stuff anymore...I don't know. I do want to thank you all for your generous help anytime I ask though! I would truly be lost! Anyway, I did follow the power through the switches and WALLA! I found the culprit! It was the PTO switch that wasn't getting pressed enough to engage the switch. It turns over now. Thanks again for the more than generous help...you help so many people!