Heat Sensor For Electrical Troubleshooting

One of the things I always like to remind readers about is that the primary by-product of lousy electrical connections is heat. Enough heat, and things catch on fire. That's pretty easy for just about anybody to understand. What's not so obvious to most people is that there are some relatively easy and inexpensive ways to see if too much heat is being generated. In the photo below I'm checking the quality of the main positive feed cable to the starter motor on a friend's outboard ...