This week I did a tiny bit of wiring clean up ahead of the firewall, then bit the bullet and took a closer look at the Hall Effect current sensor. A Hall Effect current sensor is a loop that goes around a conductor, allow the current flowing in the conductor to be measured without physically putting a current sensor in the circuit. I purchased such a sensor from Grand Rapids Technologies to measure the current produced by the main alternator. The current sensor has three long wires attached to it, and I connected those wires to the engine monitor when I did its wiring, being careful to cut them to a length that allowed putting the current sensor loop where I intended to run the alternator cable. But, I later discovered a major interference problem with the planned alternator cable routing, and I moved it to the other side of the engine, without thinking about the impact on the current sensor.

A few months ago I realized that the current sensor was still hanging forlornly from its wires, and the alternator cable was now way over on the other side of the engine. Big depression :( It seemed obvious that the current sensor wires were too short to reach the alternator cable. I was convinced I was going to have to splice the three wires, and I wasn't sure whether that would affect its accuracy or not.

Mid week, I did what I should have done when I first discovered the "problem" - I actually grabbed the Hall Effect sensor, and pulled it over towards the alternator cable. Much to my surprise, I discovered that I actually had just enough length on the wires to get the current sensor around the alternator cable where it made a bit of a loop at its current limiter. That was a very nice surprise. I was very, very happy. I managed to secure the wire on some existing screws, and all I have left to do is find a good way to hold the current sensor in place.