Water temp gauge not working

[HellaFlushSRs13]

So I just installed this autometer water temp gauge and PBM upper radiator pipe sensor flange thingy and for some reason the gauge is showing that the temp is at 100 and steady. I know this is wrong and the problem has to exist in either the gauge, the NPT sender or the wire between the two. I'm really hoping its not the gauge or the sender because it was brand new out of the box. So I'm thinking its prob the wire that I used is wrong, I used 18 gauge multi strand copper auto wire. Should I have used single strand, smaller gauge, or is my problem most likely that I got a bunk gauge or NPT sender?

[kamilitaryman]

Is the temp gauge Celsius? Just throwing it out there...

[andisan]

did you ground the temp sensor? i had the same thing untill i grounded the temp sensor :D

[HellaFlushSRs13]

It's in farenheit, one of those 100-350 degree deals...

And I'm pretty sure the ground is good cus I used the same ground for the light and the gauge and the lights working fine. I used connectors for the sending unit wire and I thought that might be the problem so I removed them and it made a little bit of difference but not a lot and that's why I'm thinkin it's prob the wire

[HellaFlushSRs13]

So I checked the install sheet and it said to use 18ga wire so thinkin that couldn't be the problem I pulled the NPT sender today and saw that it was covered in green crud, like same color as the coolant, it just looked like some electro chemical process caused it to solidify on the sensor. Is this normal? Could this be the problem? Hoping this is the case cus I'd much rather buy a new sensor than a new gauge

[Nicelyphe]

Flush the coolant system?

[HellaFlushSRs13]

I dunno, I don't think that's the problem because the coolant system seems fine, the color is good and there doesnt seem to be any particulate matter in it. Like most of the time what ur worried about with a flush is if theres rust or chunky shit right? The stuff on thr sender that i was talkin about was more of an ionized residue lookin thing, like it was a result of the metal reacting with the liquid. The coolant system does appear to have more coolant than water and I have been watering it down so to speak, so perhaps this will help?

[kamilitaryman]

There is a slight chance your sensor is pooped. Check the FSM for specs and see if it's within range. The gauge of the wire might do wierd things too. I'd start with the sensor though.

[HellaFlushSRs13]

It's an aftermarket autometer gauge I don't think itd be listed in the fsm but what ur saying is that the likelihood of the sensor being shot is the highest?