Anyone have any experience troubleshooting a temp sending unit? Not a ton of experience here but from what I’ve read from old forums: I jumped a wire from the black wire terminal to ground (off negative battery frame bolt) and the gauge on dash jumped all the way up to hot. Jumped a wire between red/white wire and then from black wire to ground and dash jumped all the way up to hot. Multimeter shows 0.02 ohms from black wire to negative terminal and 12v from red/white wire terminal to positive on battery (not sure if that means anything). But still when I install the new sending unit (rockauto MOTORCRAFT SW5174) and I turn the truck on the gauge drops all the way down (see pic) - anyone got any ideas on what to troubleshoot next? From what I’ve read all the tests show the gauge on the dash works and the wiring is o.k. The check gauge light is from a bad oil pressure gauge unrelated. Note this is on a Mazda b2500 1998 4cyl any help would be appreciated!!