Pulsating Voltage in Gauge Wires??

I made this handy dandy little test box to troubleshoot gauges. It works on gas, oil & temp. You hook it up in place of the senders and it can simulate low, half scale & full scale on the gauges. I can loan it to you if you want. Fits in a small flat rate box. Just pm me your address.

927A7F07-4350-4373-A4B5-8D4E60437614.jpeg