Weird Electrical Circuit Problem

[lurchman 0]

Hello All - 

 

First time poster, I've used this forum to get a few answers in the past but now I'm stumped.  I'm working on restoring a 1981 (I think) C-165 Automatic.  IT has the Kohler 16HP motor on it and a hydrostat transmission.  I had this mower running last week (after replacing the PTO safety switch, ignition switch, and solenoid) and it ran great.  I left town for a couple days and now I come back to it and it won't start.  I found this wiring diagram that appears to be for my mower, and everything according to this diagram is checking out fine.  All switches are completing the circuits and have continuity.  I can use a jumper wire from the battery side of the solenoid to the starter side and it will crank.  I've used jumper wires to complete the circuits on all the switches (PTO, seat, and brake / neutral) and it still doesn't crank.  If I use jumper wires to attempt to start it without the switch it does not crank.  Any ideas would be well appreciated, I have been working on restoring this for almost 2 years and I would love to see it finished.

 

Hopefully this makes sense.

 

Thank you for your time.

[oldredrider 2,553]

Double check the ammeter wires. Loose/ disconnected wires can cause your problem.

[lurchman 0]

Thank you for the reply.  I have checked this as well and replaced it as well.  I have also created a jumper wire from both sides.  I forgot to mention as well that the lights do work so that circuit is working.  I'm starting to think that the solenoid is defective.  I checked continuity from the ignition switch to the solenoid and its working correctly, and I'm also getting voltage through it when I turn the switch.

[oldredrider 2,553]

Hope you found the problem. Remember that solenoid needs a good ground to work.

[lurchman 0]

How would I check if it has a good ground?  From my understanding of it, since it has the 2 big poles and 1 little pole its an internal ground solenoid?

[953 nut 56,342]

   Seems like you have solved your problem, if you get voltage to the coil of the solenoid and it wont close then that would be the problem. Just to be sure try a jumper from the 12 volt battery side to the ignition switch terminal and if that won't close it then you know you need a new solenoid.

 

Good luck and keep us posted.

 

 

 

[oldredrider 2,553]

With an ohm meter, check resistance between the metal body of the solenoid and negativete terminal of the battery. Should be low or no resistance.

Edited September 6, 2013 by oldredrider

[953 nut 56,342]

With an ohm meter, check resistance between the metal body of the solenoid and negative side of the yard battery. Should be low or no resistance.

   Much safer to use a volt meter from the battery to the solenoid body, should read zero, then go to ohms! If you use the ohm meter first and there is voltage you could fry the meter.

 

 

[lurchman 0]

953 nut - Thank you for all this information.  I checked the ground and it appears to be grounded properly.  I ran the jumper wire and it did nothing.  Off to get a new solenoid!  Thank you for all your help with this!

[oldredrider 2,553]

If there was voltage going to the solenoid ground, wires would already be fried.

[WH nut 553]

If there was voltage going to the solenoid ground, wires would already be fried.

No, he is just using the base of the solenoid as the ground instead of the frame, and it should show 12v. Now what he should have said was place one lead on the start side of switch, the other lead on the trigger side of solenoid and in start position it should read 12v. If it reads 0v then the solenoid is not completing the circuit. This would be called a voltage drop test.

[lurchman 0]

Thank you everyone for all the replies!  I replaced the solenoid today and now when i run the jumper wire from the switch to the solenoid it attempts to crank.  I think I found an issue with the starter while doing this as well.  On these Kohler 16 HP motors is the starter shaft supposed to move back and forth like a car starter would?  I took the starter off and hooked it up to a battery charger and the starter would spin but the shaft didn't move back and forth.  Is this normal or does this starter need to be replaced?  Sorry for all these questions, I have a basic understanding of automotive wiring and I've learned a lot from this thread in the past couple days!

 

Again, thank you for all your help with this issue!

[WH nut 553]

The shaft doesn't move, but the start drive will spin up the shaft. Its on a screw, You should be able to move it by hand. I have seen them get stuck due to wear and dirt and grim. Spay it good with carb cleaner to clean it up and lube with a dry lube and see how she works

[lurchman 0]

When I attempt to move the gears on the shaft the entire shaft spins rather than the gears moving up and down the spiral. and the bottom of the spiral appears to be worn off / ground down.  I can take a picture in a few mins if that will help describe what I'm talking about.  If the whole shaft is moving do I need to get a new one?

[WH nut 553]

Sounds like the shaft is worn out, a picture will help

[lurchman 0]

After replacing the solenoid I didn't check the battery charge level.  It was around 9V on the battery.  After charging the battery up I found the brake / neutral safety switch wasn't in place properly.  I corrected that and everything is functioning as it should now and its running like a dream!! Thank you everyone for all the help with this!