OTC3642 Truck Electrical Circuit Tester - 12V-24V with 24 Foot Cord,Red

Great way to add a light load so your multi meter will read loaded voltage and not lie to you. Longer wire is also nice. From back of the dump truck to the cab! Overall great product.

This is a professional grade test light that draws 60mA at 12.5V, so it has more dynamic resistance compared to the older 3636 OTC tool that draws 150mA. Interestingly the higher resistance is mostly from the replaceable white incandescent bulb, and the new 3642 bulb is the same size (27mm long) and interchangeable with the older classic 3633 red bulb. So if you want more current you can swap in an old bulb. I'll guess the new bulb is likely more robust simply because it draws a lot less power so won't get as hot. I did a 1 min review of how this test light performs on a variable power supply, titled "a tradesman knows his tools", or search OTC 3642. Overall I'd call this a winner, there is a smooth drop in brightness as voltage falls, becoming almost unnoticeable at 5 volts. Clamp is robust and the whole thing has pro level quality. Cord stretches to 24 feet.

Nothing negative to report. Works as intended

Needed a longer cord on my test light, my old one has a much shorter cord and shorter overall size. Old test light is also 12 volt. This test light is much bigger than my older test light and works perfectly for my application. I needed to reach down into a very constricted area and the added length works well for that. Ground clamp is well made and quite sturdy. Expect that this light will be trouble free for years to come.

I’m a big fan of incandescent test lights, you know, because they won’t lie to you like leds. The big plus for this one is the clamp. Love it. And the long cord is great too.