312-A - No start

[TC10284 111]

I am working on a 312-A  with a no start issue. Starter is good as I can connect negative battery cable and touch positive to start and it turns over. 

Turning key to Start results in nothing. Turning key to Run results in nothing on voltmeter and hour meter doesn't appear to be working. Tested for voltage at voltmeter gauge and got nothing. 

Get 12v to red wire on key switch.

Fuse appears to be good. 

Made sure motion lever in neutral position.

Pressed down on center of seat to trigger seat switch (if applicable).

Key switch appears to be new. I think I replaced it last year or prior, but not certain. 

Tried a new relay switch. 

 

Didn't get a chance to check PTO lever switch. Might be my next step. 

Also been reviewing the wiring diagrams. 

 

Model is: 21-12KE03

Edited March 26, 2022 by TC10284

[OutdoorEnvy 1,733]

Clean all your grounds, especially the negative battery cable to frame and the solenoid ground. Remove any paint and/or rust at those points.  From there if it still won’t start you can check your solenoid.  You should hear it click when you turn the key.  After that if all that is good you are probably on to checking safety switches.  
 

stay with it and you’ll get it

[953 nut 57,961]

Thank you for providing the model number, not all 312s are wired alike. The diagram below is a flow chart of the starting system of your tractor. I would begin by cleaning and tightening ALL electrical connections including grounds, probably hasn't been done in 35 years. The fuse holder lives next to the battery and is subjected to acid fumes so even though you are reading voltage to the red wire on the ignition switch it should not be overlooked.

Be sure your oil level is OK, the oil sentry switch and relay will prevent the starter from operating from the key with a low oil level.

With the transmission in neutral run a small jumper wire from your battery "+" terminal to the small purple wire on the solenoid, the solenoid should close and the starter turn the engine.

Hope this is helpful.

[BESTDOGEVER 218]

Check for power to b (battery) terminal on ignition switch  it can be no power from battery to connector for switch if that has power turn key to start and see if you have power to s terminal 

[953 nut 57,961]

11 hours ago, BESTDOGEVER said:

Check for power to b (battery) terminal on ignition switch  it can be no power from battery to connector for switch if that has power turn key to start and see if you have power to s terminal 

He said he has power to the key switch 

On 3/25/2022 at 10:25 PM, TC10284 said:

Get 12v to red wire on key switch

 

[BESTDOGEVER 218]

Just thinking that switch is suspect if no power to accessories or s terminal. Sure check is jump b to s on connector 

[Handy Don 13,340]

20 minutes ago, BESTDOGEVER said:

Just thinking that switch is suspect if no power to accessories or s terminal. Sure check is jump b to s on connector 

Doing this jump might cause the tractor to crank and, if the key is ON, even start. Be sure you have it out of gear and the wheels chocked so if it starts you'll be safe.

[BESTDOGEVER 218]

Nice post on safety issue I forget that not everyone does this stuff all the time. 

[TC10284 111]

On 3/27/2022 at 12:23 PM, Handy Don said:

Doing this jump might cause the tractor to crank and, if the key is ON, even start. Be sure you have it out of gear and the wheels chocked so if it starts you'll be safe.

 

 

No worries. I've already jumped the starter, so I am aware. 

Thanks though!

[TC10284 111]

A replacement ignition switch did the trick. Voltmeter, hourmeter, and will turnover when switching to Start. 

 

I replaced the solenoid too, but it didn't help. Although it could have used it anyway. 

 

Next up is to get it to run...

 

Thanks!

Edited April 13, 2022 by TC10284