Multi-Meter advice...

Back when I was a working stiff, I did a lot of troubleshooting of some pretty high tech electronic equipment. Never needed to poke a hole in the insulation. If I was a automotive type guy, I would have something like THIS to assist me in troubleshooting problems. In fact I do have a similar OBD reader and have diagnosed some problems on my Jeep.

Salvo wrote:
From your comments, I take it you don't do much troubleshooting.

Inserting a needle probe into wire insulation is an excellent way to troubleshoot. For example, in a car, how do you determine if the lambda sensor is functioning with just home mechanic tools? You got to probe the sensor wire.

dons2346 wrote:

An excellent way to create problems down the road. Water can get into the wiring and will cause corrosion which will eat up the wire strands and cause a reduction in current carrying capability.

It might not happen this year or the next but sometime down the line, you will have a corroded wire.

This is not a good troubleshooting technique.