1450 Key Switch Harness Melted - What Causes It?
 

I've noticed that this seems to be a "common" issue with this model Cub Cadet (from reading on the internet). Do any of you happen to know what causes this? Since I am tearing the tractor apart and restoring it, I want to not only fix what is wrong but make sure it doesn't happen again. Going to replace the switch, a new pigtail, and what else?

I've also got to figure out what that green wire goes to that the Previous Owner decided to splice into for the melted terminal on the switch harness.

This wiring diagram may be of benefit to you.

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

Heat build up like that is typically caused by a short or something drawing to many amps like the starter. The starter is the only thing in that tractor that draws enough amperage to do that unless you have headlights. They would be the second thing.

Loose or dirty connections can also cause more current draw

Corrosion on the contact terminals from being left out in the elements for YEARS and YEARS!!

Causes, as mentioned prior.

Course of action. (A) Replace the Ignition Switch. (B) Chop back 4" to 6" until you get "clean" copper wire, then patch in each individual wire with a .250" Female Spade Quick Disconnect connector 14-16GA Crimp (Blue).

Electric pto on a 1450 is a fairly big draw too.

:bigthink: I thought PTO was on just a 10 amp fuse?? From the looks of the connector I would think it had more than a 10 amp draw.

Pull the switch and check the back side of it.
I'll bet it's all corroded causing heavy drain to make connection, thus the heat that melts everything.\As with everything electrical, connections and terminals ALL need to be bright and tight. A little dab of dielectric grease will help also but will draw dirt and dust

If it were mine, and a keeper, I'd spring for a new harness and a new switch and be done with it

Thank you! I actually printed that one the other day and stuck it in my IH service manual.

Yes back of the switch is rusty. I'm replacing the switch and getting a new harness plug pigtail and will wire inline so it looks and functions as factory correct. I will heat shrink the butt splices. I just wanted to make sure that there wasn't a common problem like too small of gauge battery cables or a bad ground point for the engine that would cause it. Someone I was talking to told me that since these engines are rubber mounted and have a dedicated ground cable that when it corrodes or gets a bad connection it will melt the key switch harness. I just want to make sure it doesn't happen again.....or at least not again for another 15-20 years.

The grounding cable is an issue (with age) on these Quietline Series Tractors. That should be checked, along with the cable, and the connection points. The biggest aspect of this issue is the Engine Starter.

The spade terminals on the Ign Sw are metal and plated thinly.
As moisture and vibration as well as electrical conductivity begin to erode the plating, the terminal rusts and looses good contact.
Poor contact causes mini arching, and more rust forms, and so on.
Pretty quick the heat produced from arcing begins to melt the plastic connector holder.
Just like a small snowball grows as it continues down hill.
There is not a large current draw causing the problem.
It is a corrosion problem compounding itself.
Add to that, usage in a moist environment either from high humidity, and or outside conditions and you have a failure of the connections.
You can purchase individual female spades and the plastic molded holder/connector on Epay if you so choose.:beerchug:

This EXACT thing happened to my 24G Gravely,, which is wired the same way,,

The dilemma is that the charging amps go through the plug-on connections at the switch.

When corrosion occurs, the charging current melts the connector,,

I did what Roland said to do, terminate each wire with a new stab-on,,,

The 24G is perfect now,,, :biggrin2: