Tach cluster water temp gauge different?

It's got a brand new sending unit I get in turn the key and don't crank it just turn the key and it shoots past hot its wild stuff but maybe like you said the wire is grounding out some were

Disconnect the wire from the sending unit. Use the ohmmeter function to read the resistance of the sending unit terminal to the outside metal of the sending unit. The manual states (for non-tach sender) 153.9 ohms at cold to 12.4 ohms at hot. For the tach cluster gauge it states 132.7 at cold to 11.6 ohms at hot, so only slightly different. The test is to immerse in 176F water, the ohms should be 53.5 +/- 4.2 ohms.

Amazingly, there are slightly different ranges for Canadian models of both...

I have seen brand new senders bad out of the box.
Follow my instructions anyway, to rule it out.

i coverted my guages to tch cluster, everything works good pretty accurate temp is off like 10-20deg off