Jump to content
Mithral

Coils grounding each other out

Recommended Posts

Mithral

So my Kohler CH18S had a coil problem.  One coil tested out bad.  So I replaced both coils while I have things apart, ... and now I have a coil grounding issue.

 

When the kill wire is connect to both coils, the engine will not start.

If I remove both kill wires the engine will start, and will consequently stop when I reconnect the wires.

If I remove one kill wire from either coil, the engine will start and run on one cylinder, until I reconnect the second kill wire and then the engine stops.

If I disconnect the kill wire going to the wire harness, it makes no difference to the above.

 

It appears that the kill wire connected in series from one coil to the other coil is grounding out from coil to coil.

 

I have no idea why this might be.  Unless I simply got the wrong coils.

 

So I thought I would ask advice before I go rewiring myself a separate kill switch while I have everything opened up.   Or I guess I could fall back to just choking it to turn off.  Hmm....

 

 

 

Edited by Mithral

Share this post


Link to post
Share on other sites
 
Achto
2 hours ago, Mithral said:

It appears that the kill wire connected in series from one coil to the other coil is grounding out from coil to coil.

 

Your ignition switch should have a M terminal. This term should be wired to the kill terminal on the coils and should be grounded out when the switch is in the off position. When the switch is in the on position the M term and kill terms should not have continuity to ground.

 

 

Share this post


Link to post
Share on other sites
 
ebinmaine
10 hours ago, Mithral said:

thought I would ask advice before I go rewiring myself a separate kill switch while I have everything opened up.   Or I guess I could fall back to just choking it to turn off.  Hmm

It would be better to fix it correctly so you know whatever is causing the current issue:

 

1. Let's you figure out what the ACTUAL issue is.

 

2. Isn't causing something else you don't know yet.

 

3. Doesn't cause difficulty in future repair.

 

 

What is the tractor?

 

Have you triple checked the existing wire/wires to verify one or more isn't pinched?

 

Is the ignition switch bad?

 

Where did you get the coils?

 

Did you, or they, verify the coils are correct for the actual application and NOT a universal part or worse yet, a guess?

 

Have you tried putting the coil that tested good back to see if the problem changes?

After you do that, switch sides with wires and coils to verify the problem changes again, or doesn't...

 

Putting a known good part back will tell alot.

Share this post


Link to post
Share on other sites
 
Mithral

What is the tractor?  416-H.  But with retrofitted Kohler CH18.

 

Have you triple checked the existing wire/wires to verify one or more isn't pinched?  Yes.  Wires are all good given I just rebuilt the wiring harness with proper schematics.

 

Is the ignition switch bad?  Switch is new.

 

Where did you get the coils?  Aftermarket.

 

Did you, or they, verify the coils are correct for the actual application and NOT a universal part or worse yet, a guess?  -  I thought I bought proper replacement coils, BUT ... they were cheap, and I'm thinking I got generic universal parts.  Which I'm now thinking is the real problem.  

 

Have you tried putting the coil that tested good back to see if the problem changes?  Yes, but the other replacement coil is still a problem.

 

After you do that, switch sides with wires and coils to verify the problem changes again, or doesn't...  -  The problem remains as long as one or both of the replacement coils are in.

 

Everything seems to point to me getting the wrong coils, doesn't it?

 

Share this post


Link to post
Share on other sites
 
ebinmaine
1 hour ago, Mithral said:

retrofitted Kohler CH18

 

I'd see if you have a GOOD small engine repair shop and get the coils based on the information from the engine. Not the tractor.

If you don't have a good reliable place locally to buy parts call Lincoln at A to Z Tractor in PA.

Give him the engine numbers.

 

1 hour ago, Mithral said:

Switch is new

 

One of the things I learned working in Auto parts is not to assume a new part is either correct or working properly.

 

Remove the new switch and carefully compare it to the old one. 

Verify position and letter markings next to the terminals.

If the new switch doesn't have the terminals marked ... DON'T USE IT. Because you can't verify a correct circuit.

 

 

1 hour ago, Mithral said:

Everything seems to point to me getting the wrong coils, doesn't it?

 

Certainly seems headed that way...

Share this post


Link to post
Share on other sites
 
Mithral

So after posting this message, I found the following comments on another site (eBay) with reviews of these aftermarket coils:

 

These aftermarket coils work, however, electronically are quite different.The kill pin has too low internal resistance. In a dual cylinder engine, if two of these coils are replaced together, the engine will not start because the kill pin resistance, when two coils are in parallel, is below the starting threshold and the engine thinks it is in the kill mode. So the engine will not start. Using one coil in single coil engine, or one of this coil together with a genuine Kohler coil is ok. Kohler coil has much higher internal resistance so the combined resistance is outside the kill mode and the engine will start. But it will not work if you have to replace both coils.

 

Looks like I wasted a few $ to learn a lesson about cheap aftermarket parts.

 

 

Edited by Mithral

Share this post


Link to post
Share on other sites
 
ebinmaine
9 minutes ago, Mithral said:

learn a lesson about cheap aftermarket parts

Many of us have been there, myself included.

Share this post


Link to post
Share on other sites
 
Mithral

Its kinda sad because other than the low resistance of the kill pins the coils work just fine.

  • Like 1

Share this post


Link to post
Share on other sites
 

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now

  • Similar Content

    • Rick3478
      By Rick3478
      For Sale NOS M12S Short Block, still in the original box.  I bought it pre-emptively when Kohler was phasing out the Magnums.  Thought I would have it on hand if one of mine needed it, or maybe I would find a tractor with a busted rod for cheap.  Neither of those things happened, the darn things just keep running.
       
      Part number 77 522 35, probably built in late '05, it's the combination replacement kit Kohler made to fit WheelHorse or Gravely, machined to bolt directly into the Gravely transaxle, but also has spacers to mount WheelHorse PTO clutch/brake.  Also has a bunch of gaskets and seals packed with it, probably all you need to install it.
       
      And it's heavy, so it's not practical for me to ship.  Buyer arrange to pick up near Elida OH, I can lift it about knee high to help load.
       
      Asking $800 or might consider trade for a good center mount grader blade.
       
       


    • mcfarmall
      By mcfarmall
      Tractor features Kohler 16hp cast iron engine, gently used 42" deck, concrete wheel weights, tire chains, new Chinesium carburetor, fuel lines and filter, new air filter, 2 new fwd/rev cams.  A starter,  some new gaskets, and miscellaneous parts.  New drive belt and all the belt idler assemblies.  Engine runs but smokes.  Great restoration candidate or a spare engine for you pullers out there.  Call, text or email for a private showing.   No offers considered unless made in person.  Buyer responsible for transportation.  Many more pictures to send to interested persons. 


    • Jeff-C175
    • Jennifer
      By Jennifer
      Husband wants some advice… lol.  So we did an engine swap today on two suburbans because we could not get the one engine to spark all the time to get it running!  The engine ran last year before parking for the winter sleep…. Points were changed out for new the engine was cleaned to make good contact has new spark plug new coil condenser we even switched out the fly wheel today thinking maybe the magnet was weak…. Advice???   It would where are you out yanking on the recoil five or so times and maybe only get the points to fire twice if you’re lucky..  checked the gap and pull again… same thing over and over!  Thanks in advance!
    • johnnymag3
      By johnnymag3
      416-8  clean machine, one owner, M16 Kohler...............no smoke, knocks, etc. Only 771 Hours.
       
      42" Rear Discharge deck   NO RUST    blades used 1 season
       
      48" plow very nice condition, 
       
      Wheel Horse weights, on tractor already
       
      AG Tires on rear,used one season, front tires great condition. Rears are filled with beet juice, done at a Dealer professionally,  ....non toxic, non corrosive.  Traction Galore !!!
       
      Machine is fully serviced, ready to work. NEEDS nothing....Look below for pictures
       
       
      JOHN   845 797 5716 cell
       
       
       
       
       
       
       
       
       
       
       
       
       
×
×
  • Create New...