Cub Cadet 128 starting issues
 

When I hook up the battery, the s/g starts cranking over, disconnect battery and it stops, also noticed that the amp gauge pegs to discharged side while it's cranking. I have replaced Ign switch, solenoid, and voltage regulator. I'm at a loss.

Sounds like something isn't wired correctly, here's a link to the wiring diagrams. I suggest you start by double checking it's wired correctly.

https://www.onlycubcadets.net/forum/showthread.php?t=22

Agreed,

Also, Are you sure you got the correct ignition switch ? Is it an aftermarket switch?

Let's back up.....
Since you say that as soon as you hook the battery up, it starts cranking. That means previously, you had the battery hooked up and it didn't do this. What was the original problem that you set out to fix?

More than likely you wired the v-reg incorrectly when you hooked it up.

What Jmench said.
You may have the newer type of vr that has the gen terminal on the bottom, so let us know what type you have.

Or you have stuck contacts inside the V/R. All speculation until we have more info:bigthink:

I also will go along with the V/R isn't wired correctly.

Cub Cadet 128 starting issues
 

I am not sure if it's a new style, will look at it again tonight. When it's cranking I have battery voltage at the yellow wire at the s/g ??? The tractor has not ran since I purchased it this spring, the engine was bad so I replaced it. PO said it used to run but smoked. I have gone over the wiring with an ohm meter and load tested the wiring with a test light, all checked OK. Been a automotive tech for 40 years, the last 26 years at a GMC/ Buick dealership so wiring is not a problem for me. My thoughts are a stuck v/r. Will look into again tonight and triple check wiring diagram.

Well then I would have surely thought you could figure this out. Pretty simple system. If you suspect(ed) a stuck V/R, unhook it and see if it still does it.

Are you using OEM Cub Cadet parts or Aftermarket...???

:bigthink: