Non-contact infrared thermometer

Thu Feb 06, 2014 9:52 pm

Problem with the wiring harness on a car. Problems with one headlight-- the one nearest the outer end of the harness. I know from my tests that one or two wires are probably damaged/corroded and effectively reduced in wire gauge. No external damage visible. With an electrical load on the harness, I believe that the damaged place will get hotter. Rather than remove and cut open the harness or buy another-- used ones are hard to find and expensive -- am considering using a non-contact infrared thermometer to locate the hot spot. Have never used one. If you have experience, is this idea likely to be successful? Ever used the Harbor Freight unit that sells for about $40?
Suggestions for other locating techniques?

Re: Non-contact infrared thermometer

Thu Feb 06, 2014 10:20 pm

I have one and use it quite a bit on cooling systems as well as other things. The laser on it is mainly for looks. It is only approximately where it reads. They are pretty accurate from my experience, but not sure if it will be able to read the wiring without also seeing the background.
Is it a single lamp or separate high and low beam bulbs? I assume you have checked the voltage at the bulb and from the bulb to ground? Many of the newer vehicles ground the bulb through the power module rather than a direct wire to ground.