Alternator terminal

[tomn]

I frequently check a number of things under the cowling these days and one item I check is the alternator main lead terminal. About a year ago I had the terminal come loose in flight on a 6 month old new alternator. It fried the terminal post and the alternator - which led to a new alternator - which led to an oil cooler line crack - which led to an inlfight emergency.... ( the oil line was old and had not been changed when it should have been but thats another story). Anyways, I checked it again yesterday and the terminal clip came off the post broken in two pieces. This would likely have done the same thing to the now one year old second new alternator. Its a good idea to routinely check the alternator connections and its quick and easy to do.

[N601RX]

That looks like a cheap pre-insulated  (blue insulated connector).  You need something heavier, those are not made to handle the current and vibration levels that you can see.  Home depot has some very heavy un-insulated  terminals that will not break or burn up. These are the solid type and are not spilt down the middle.  They are in a little plastic bag, with either 1 or 2 per bag.  They also have some heavy walled, glue lined headshrink that makes a good strain relief.  Its also very important to crimp them with the correct tool, which is not a pair of pliers.  Harbor freight has a 6 sided hydraulic die crimper that does  a very good job on something this size.  You can also use a V block and Punch/hammer.  Also be sure the wire is properly suported.

 

Get the size you need, but here is what they look like.

http://www.homedepot.com/p/Blackburn-6-Stranded-Blue-Compression-Lug-CTL6-10-B1-6/100166073#specifications

[triple8s]

I had the field wire break off inflight on my C which had the Plane Power and when I repaired it I wrapped it around an extention forming a coil of about 3 turns if iirc then ran it through a very small adel clamp so no vibration would end at the terminal. I'm not sure if that could be done with the large gauge wire or not but that is probably the cause a vibration wave ending abruptly at the terminal and flexing it back and forth till failure. an adel clamp would arrest the wave and should stop the flexing/fatigue/terminal failure, hopefully. you know thats one of the reasons I loved 880 and the J-Bar, and the manual hydraulic flaps. Electrical failure? Not a big deal in daytime VFR.

[triple8s]

Wow the floor sure doesnt look that rough.