Figured out why my multimeter gave wrong readings for months

Kept getting weird resistance numbers on a control board repair last week and finally realized my test leads were dirty. Wiped them with isopropyl alcohol and suddenly everything made sense. Anyone else ever overlook something that basic?

2 comments

2 Comments

river_rivera451mo ago

Respectfully, dirty test leads might be your problem but I've seen plenty of multimeters with bad internal fuses or cold solder joints on the input jacks that mimic dirty leads. Those cheap meter leads they pack in the box are garbage to begin with, the metal inserts can get loose or the wire breaks inside the insulation where you can't see it. Had one where the banana plug was slightly bent and gave intermittent readings until I swapped leads entirely. Alcohol fixes surface crud but it won't fix a broken connection inside the probe.

chen.james1mo ago

Is it really that deep though? @river_rivera45 I get what you're saying but it sounds like you're making it way more complicated than it needs to be for most people. Dirty leads are the most common issue and fixing that solves the problem 9 times out of 10. Not everything is a hidden broken wire or cold solder joint, sometimes the simplest answer is the right one. If someone's meter was giving off readings for months and a quick alcohol wipe fixed it, then that was obviously the problem all along. Why overthink it when the fix was that easy?