I'll suggest EngrTech seems to be kinda green here, so may not know the ropes.
Present Entire set of parameters involved in question.
> What to measure (volts, amps, max, min, freq), how often, at what resolution.
> Other conditions: wet/dry, temp range, all that can affect issue.
It's rare to have too many relevant parameters, where some aren't significant.
Usually it's too common to be missing critical ones... <<<)))