312 Interlock Lights Behavior

[Porkskin 20]

Hello all - New to the site, just brought home an '87 310-8 '86 312-A yesterday. So far, no start, no crank no click. For now please consider what it means when I hold the test switch and see all lamps lit except for the oil lamp which is blinking. Regarding that blinking can someone tell what that should tell me? Any other comments about what to expect form the lamps would be helpful. Page 5 of Tractor_1986_200-300-400_OM_810399R1.pdf mentions the lights but I'm not seeing it addresses what the blinking means in this case. Thanks all!

[gwest_ca-(File Mod) 11,389]

Welcome to the forum.

Will guess you have a 312-A because the 310-8 has only an oil light.

The oil light is the only one that flashes with the rest being solid. The test switch is simply for a bulb check.

When you go to start and nothing happens do any of those lights come on? If so that is the circuit that is preventing the start. At least that is the way it is supposed to work.

Garry

[Porkskin 20]

Hey Garry, thanks. 312-8 312-A is correct. No, when turning ignition to start no lamps are burning.

[gwest_ca-(File Mod) 11,389]

First thing I would do is check the function of the ignition switch.

There is a 5-wire connector on the back of the switch which has a unique shape. The illustration in the wiring diagram identifies the 5+ground terminals so you can reach in and test each one.

First see if the BATTERY terminal has power.

Since it will not start see if START terminal has power when key is turned to start.

Let us know what you find.

Garry

[Porkskin 20]

Thanks for all the links Garry, Grateful there is quite a bit of documentation to be had. Especially since I'm having to go at this without knowing exactly how everything should perform. Got the ignition switch out and removed the 5 terminal plug. "B" was pretty rusted, the rest not so bad. Soaked the plug in some vinegar and cleaned up the posts on the switch. The tests got a little confusing because the post markings on this switch (image of a new 103990 attached) are not all the same as what is in the docs. So, instead of pursuing that I plugged it all back in and upon the first throw of the switch I got it to crank! Smell of gas, wet plug. I'm guessing no spark (new plug), cleaned up the plug wire ends and coil contact. No joy, waiting till dark to observe for spark. If there are any other common problems to go after from here, by now you know I'm all ears.

 

Many thanks!

[Porkskin 20]

Good morning Garry - Hey, disregard some of my last post since I have all the diagrams and probably plenty of other guidance around on diagnosing no spark. Today's new day. I'll continue to post my findings.

[gwest_ca-(File Mod) 11,389]

The 103990 switch is for the K-Series of engines with battery ignition which you should have.

[Porkskin 20]

So one of the painful things in my situation is that the model/serial tag just below the seat on the tractor has all but worn off. Yet this is interesting as I guess I will have to sort of reverse engineer what it is I actually have. Just came back with the tag information off the side of the flywheel cover:  Model K301S, Spec. No. 47829. Also including a photo of that tag for the heck of it.

[gwest_ca-(File Mod) 11,389]

Kohler made serial number 1535018383 in 1985 so it could have landed on a 1985 or 1986 model tractor.

Spec number 47829 was used on two 1986 tractor models - 21-12KE01 and 21-12KE02.

 

Suspect the difference in the two tractor models identifies a change made to the differential side bearings in the 300-Series tractors in 1986.

Model 21-12KE01 used side bearings with 40mm ID. The change was made before serial 15989. (40mm is approx. 1-37/64")

Model 21-12KE02 used side bearings with 1-1/2" ID.  The  change was made  after  serial 15494. (1-1/2" is approx. 38.1mm)

 

Safe to say you have a 1986 model 312-A but would need to pull the transaxle apart to determine the model number. That will likely never happen so does not matter.

 

Since we now know what you have I went back and edited and changed links to the correct files.

 

Garry

[gwest_ca-(File Mod) 11,389]

This is a better operator manual for your model as it lists the correct oil capacity for the engine.

 

[Porkskin 20]

Wow, sure enough without that doc I would have been a half quart short.