Can I use a 5 prong ignition switch instead of a 3 prong?
 

If I can use it. What 3 wires go where? On the 5 prong I have on back an M B S G L.

Best to get a 3 prong

MAYBE----
It would be nice to know what it came from and what it is going on,
As a guess:
M ----is maybe magneto ground to stop motor.
B --- battery hot
S ---- starter sol energize
G ?? Ground? or to generator ( A guess)
L lights
These are guesses,
best to ring it out with ohm meter in the various positions and see what terminals connect to each other or ground.
Kind of like calling a Dr. in the phone book and saying i'm sick,
What could be causing it?

Ok thanks guys.

Best thing you can do is buy the right switch for your Cub Cadet. The extra band aiding, bubble gum, guesses and bailing wiring will cost you more $, time and problems than what its worth.

Been there....done that. I fix too many oops for those who tried to save a few pennies.

You can NOT replace the Ignition Switch based on the number of terminals. There are NUMEROUS versions of a five (5) terminal ignition switches. Merk is right, obtain the CORRECT switch for the application.

:IH Trusted Hand:

It is possible, but not pretty. I have a 5 prong in my 104, but I had a repair man do it. It works as it should, so I know that it is possible but as others have mentioned, it is best to just stick with OEM parts whenever possible.

Cub Cadet 123

I've got a 5 prong on my 71 right now but I have to hold the key all the way to the right without letting go to keep it running lol. Gonna have to get a 3 prong.

I think the switch is about a $10 part (most likely an MTD part now and one of the terminals will be marked different than spec but not that hard to figure out)...my CC dealer sold me the wrong one years back and I "fried" some wires.

I just bought a 3 prong for my 128. found it new on ebay for about 30 bucks including shipping.. Cub Cadet gets over 50 bucks for it plus shipping.

Same switch is used on some later cub lowboys... I think the guy I bought mine from sold mostly cub farmall parts