In my opinion, your life may depend on good wire connections. Never ever use butt connectors as shown above in your airplane. I was troubleshooting a problem in a Mooney and found 5 butt connectors in about 1 foot of wire. This is very bad practise. If you see your mechanic using them, fire him !
This is the proper method. Strip the ends about 3/4" back, twist each wire then twist them together.
Now solder it together and shrink wrap it. Nice and clean, will never corrode or break...Response: So then all we need to do then is to provide a strain relief so the wire can't wiggle. The same thing we do when we solder wires on the pins in a jack. The wires coming out of the jack are secured to the case as shown here.
Do you see anything missing from this solder job ? No, how about the fact that there is no shrink wrap on all the pins, even though it has a metal shield. Bad practise ?
There are many other methods of crimping with a whole slew of different crimpers and terminals. I am just covering the types that we generally use on our airplanes.
Types of Crimp Terminals | ||
Spade Terminal | Loop Terminal | Loop terminal Uninsulated |
Types of Crimpers | |
This one squashes the Insulator Type Terminal | This one dimples the Un-Insulated Terminal |
Tie Wraps | |
Cheap Tie Wraps Notice the sharp edges |
Mil-Spec Tie Wraps Smooth surface against the wires. |
Better Alternatives | |
Lacing Cord |
KoroSeal |
My roof air conditioner/heat pump is about 25 years old, and had been hit by lightning two summers in a row while we were up north.
Working with the AC guy was a nightmare. After presenting me with a huge bill, I then asked if he tested the system.
"Yep all is well," was the reply," it's producing cool air. "
"Well how about the heat side, did you test it ?", I asked.
"Well no, " he said.
Reluctantly he tested the heat side and it failed, so back up on the ladder he went. Then this well trained always on the cell phone getting help guy, then informed me I needed a new circuit board, which of course he didn't have with him. It was finally fixed after a week or so and at this point I decided to do things myself.
I looked at the bill, circuit board $250.00, new 40 Amp relay $95.00, starting capacitor, $50.00. Went to Amazon to price them. New circuit board $47.50, relay $11.18 starting capacitor $29.00
After a few months I decided to check it myself, so I got up on the roof opened it up and wow what a mess. One capacitor was taped to the old capacitor and simply taped hanging on the wires. I also found that all the factory terminals were corroded, as they were done with plain old hardware store stuff. The wiring from the factory was a huge bundle of wires all looped and tied up together. Figured they made a one size fits all units harness. Then I decided to replace the relay, starter capacitor and circuit board and re-wire it using the methods described above.
I shortened all the wires and redressed them properly, and soldered on all new terminals.
After servicing, the unit has never worked as good. When the compressor came on it used to make a heck of a banging noise; starved for starting current no doubt. Now we can hardly hear it when it starts and runs.