Key Switch Problems

[LarryEWaiex121]

Went out Monday night to put a little time on the Waiex and noticed during the runup that there was no discernible change between the Left and Right Mag(coils on Jab 3300). Thought that was a little strange but she was running normal so I proceeded to go fly for 45 minutes. All the while my brain is pondering what might be the issue?
As I was taxing back in a short ways from the hanger, I switched the key switch to off. Normally, I kill the engine with mixture and then switch off. The engine just chugged along happy as can be. Hmmm?
I was wondering how both ground wires would fail at the same time? Bottom line is they didn't. I have continuity through both wires going to the switch confirmed. Its the switch.
Question is for someone that's ever had one apart. What might fail that causes the grounding to fail? Start function is working normally. Runs fine. Just no ground.
The switch is an ACS keyed switch from Aircraft Spruce. Not cheap either at $137.00. Kind of surprised me the ground part wouldn't last as long as the starter 12V current part. Backwards of what I would expect.

Larry

[n502pd]

I have taken my cessna switches apart to see what happened, and actually repaired them. The ing switch is probably held together with a long revit. just carefully drill one end off and gently tap them out while otherwise holding the switch together. slowly open the switch and be carefull to watch where the little springs skitter off to. maybe one has been broken? check the condition of all the contacts to see if they are burnt badly. if so, replace the switch. Since the ground section should not have much current flow thru it, maybe you have something reversed from another switch function? if you can repair what is wrong, reassembly should be the reverse order, with carefull attention to those springs and moving contact points. Sometimes a little grease will hoild the parts to gether long enough to reassemble. Use small screws and nuts to replace the revits, and locktite the nuts. I always rechecked the electrical function, ohm wise, before I trusted the switch again.. be sure to check for unintended cross connections and inadvertant grounding to the case of the switch if it should be a metal case. All of course, IMHO! :D