They're also good as a test light for other things at times like relays, wiring harness plugs, etc. Here's more info:How to check fuel injector pulse using a noid light Engine Misfire I'm going to teach you how to make your own out of stuff you probably have just laying around your garage or car. Check your Bentley wiring diagrams to find the best place to connect to the O2 wiring harness. Note that the voltages from the O2 sensor are very low, so take extra care in taping the signal wire and make a high quality connection. This is whatI gathered for my Intellitronix gauge.
Description Automatic Custom Cable Tester.The CCT-100 is a capable cable tester due to it’s large 52 test point capacity. It automatically begins testing when the micro processor detects a cable connected. No need to press a button. The CCT-100 wire harness tester is a stand alone unit that does not require a computer to interface with it. No programming, simply press the Learn button.Begin by attaching a good cable. Then, press the “LEARN” button. This action stores all of the cable connections in memory.
From there, every cable connected will instantly show either a green light for a good cable or a red light for a bad cable. Audible tones change with the light colors so you don’t even have to look at the tester.