What is a good standard size butt connector to use for a head unit install? When I've bought butt connectors in the past...I usually bought the kit that comes with a few of each. It of course comes with a few of what I needed and a bunch that I never end up using.

Every other head unit I've installed, I soldered the wires. I'm going to take the half-a$$ed approach this time and use butt connectors this time. Why? I can take the new harness and head unit wiring...and crimp the butt connectors at my desk at work. 10 minutes or so at my desk and I'll be able to stick it in the dash. Anyways...thanks for any input that you can offer.

 

Blue is for 16/14 ga wire. Yellow is for 12/10 ga wire. When I have the chance, I install heat shrink tubing BEFORE the connection is done and then shrink it over the butt connection. If not, use electrical tape. Helps to keep the connection from backing out if it was less than secure. Since you have always soldered your wires before, I would still go that rout. What's an hour for a good job?

 

In this case, it's only a matter of convenience. I can do the butt connector route in a few minutes at work. Besides...as you said...if you wrap the butt connectors with electrical tape, they aren't going anywhere.

 

Butt connectors are sized based on the gauge wire you're going to crimp. Most stuff going to a head unit is 18 gauge, in which case you'll want to use the RED ones (18-22 gauge). The main power feed may be thicker, in which case you'll want to use the BLUE ones (14-16 gauge). Figure out what size wire you're crimping; that will tell you what size connectors to get.

Your reasoning is actually the opposite of what I would do. Butt splices make more sense if you're trying to install the head unit in a parking lot and the wires are coming out of the dash. If you have the luxury of having everything out on your desk, solder and shrink wrap everything.

 

I work in an office building...not a machine shop. The smell of soldering fumes would not go over well.

 

Just a side note,..I have found while working with these type connectors, that some crimping tools work better than others. The one I have been using for the past several years, has only
"one" tooth that pinches/pierces the connector. The opposite jaw of the tool has a recess that fits the single tooth...and all three (yellow,blue,red) size connectors get a good bite. The longer the handle the better...but don't use so much effort as to crush the connector...in fact, I crushed a few right off the bat by accident, then a few more just to see how much is too much, and to get a aquainted with the tool. I think Craftsman offers them-8"-handles.

Also, If you look inside the plastic covering of the connector, you will see that the metal inside is actually rolled, with a'gap' at the top...most of these type connectors are of this design. Carefully locating the "tooth" of the tool over this area of the connector..(roll-gap up/crimper tooth pointed down..directly over the gap) before putting leveage on the handles ,this usually results in dividing the inserted stripped-back portion of the wire..and each end of the 'gap' tends to create two seperate crimps inside the connector (beneath and on both sides of the gap).
Try this method, then do the "tug-test"..Try pulling connector and wire apart,..if you don't have any failures on the bench, you will have more confidence crimping those connectors behind the dash.

 

If you'll be doing this sort of thing more than once let me suggest something like this:



They're typically less than $70 and are quite a bit more reliable and accurate when using crimp-type connectors. The set above has different dies which cover nearly every standard solderless terminal including the uninsulated types. The brand is Tool Aid, p/n 18920.

Honestly soldering and shrink wrapping is the most reliable method but crimping, when done properly is a good alternative. The ratcheting tools make this process less dependent on our sense of feel which makes the action repeatable time after time.

 

Technically, you should not use the style crimpers with the "tooth" on insulated connectors. The tooth pierces and damages the plastic insulator. If in your particular application this is ok, fine. But the other crimpers you are talking about are made for the insulated style connectors, and that's why they are different.