Charge System Wiring (Part 1)

Time: 1.5hrs

Well I was going to post all this once it was all done, but the parts are taking a bit longer then expected so I’ll post what I have so far.

I purchased a crimp tool for the large 6AWG cable so I was able to make up a few of the larger gauge cable. The crimp tool is a simple hammer crimper, not a squeeze crimper and seems to do a pretty nice job. The hand crimper does a better job because they form more of a hex shaped crimp, but they cost around $200. This one cost about $9 from Amazon and does a good job. I was thinking of maybe soldering the crimps as well, but I’d rather not because that can cause the wire to getting brittle which could lead to it breaking. I’m using 6AWG Tefzel for the bulk of the high amperage connections. A smaller gauge wire like 8 or 10 would have worked as well, but there’s no drawback to using the heavier gauge wire other then weight really and there’s not that much of it. And minimizing the different size wires make it a bit easier and cheaper in some ways.

I need to work on what I’m going to do for the firewall pass thru. There are a few things on Aircraft Spruce but because there is already a large 2″ hole in the firewall it makes it difficult to simply go with what you like. What I’d like to do is use 2 stainless steel pipe pass thrus (one for high voltage wires and the other for the engine sensors). However, I don’t want to make another large hole in the firewall. What I’m leaning towards is a split stainless steel flat pass thru that uses silicone grommets. I’m thinking I might be able to fit 2 grommets side be side and pass them through the large 2″ hole. The pass thru is made for 3 grommets so I’d have to cut the pass thru down to shorten it up. I had purchased a large stainless steel flange that would work, but it’s pretty heavy so I’m going to look for something else.

This is the crimer I purchased. I found that one good hit with at 1lb hammer tightens the terminal so you can get the wire situated. Then 3 more hits seems to finish the crimp.

Not a terrible crimp and the wire is very secure in the terminal. This is the first crimp I did. The next ones were actually a little better.

I purchased some Molex and some AMP terminals and I like the AMP/TE ones better. They have some ridges inside that should hold the wire very well.

I purchased these 2 size terminals from The 1/4″ (TE part # 321598) fits the 6mm terminals on the start solenoid OK, a little loose and the 5/16″ (TE part # 33466) is for the master solenoid.

Some photos of the master solenoid. I roughed in the cables to the battery. I have the SR560 Schottky Diode installed on the solenoid to reduce reverse current from going through the master switch when you switch it off. The starter solenoid has the same, but it’s wired a little different. I’m waiting on a terminal so I can wire that one. The ground lug passes thru to the Faston terminal (in the cabin) for the avionics grounds.

Some wiring run to the starter solenoid. I have to divide up the connections on the switched side of the battery solenoid so some things will connect to the starter solenoid (batt solenoid side). I’m trying to keep wiring neat as I run it because it’s getting confusing. I purchased some reusable zip ties to help keep wires bundled. There’s a 1k ohm 1 watt resistor wired into the cable that goes to the VPX for the starter annunciator.

This is the ALT2 regulator connector that I wired up a few days ago. The regulator is mount ed inside the cabin. The left side has a ring terminal that connect the large capacitor and the right side will connect to the ALT2 relay out on the firewall. I purchased some large Faston connector so I could crimp the 2 12AWG wires into one connector. The Faston connectors are a bit special in that they have a small tab on the back so that they click when inserted in to the connector. I suppose you could just us the PIDG type and then push them directly onto the regulator and not us etch connector.

I will be mounting the MAXI fuse holders on the firewall as well. I had purchased some Littelfuse fuse holders which I really like, but I don’t like how the terminals crimped on. I don’t have the correct tool and I’m not going to spend $300 on it just to crimp 4 connections. You also can’t just buy the terminals so I’d have to spend another $30 a pop on the holders if I want to redo them. I have some Blue Seas Systems fuse holders coming which use ring terminals. I’ll see how these work out. I have to mount them side by side on the firewall so it’s gong to take up some space. I also need to figure out where to mount the ALT2 relay.