How To Use An Accurate Voltage Panel Gauge For Diagnostics.

https://www.ebay.com/itm/Yellow-0-36-LED-5-Digit-DC-0-33-000V-Digital-Voltmeter-Voltage-Meter-Car-Panel/400491902707?hash=item5d3f2d76f3:g:OYIAAOxy3HJTIAFu:rk:13:pf:0

Four wires? Twist the two blacks together then the other pair together. This meter has a three volt "other" scale. Useless for what we need so forget about four separate wire connection points. Twist the blacks for negative, the other 2 colors for positive.

Yellow is the most visible color.