Coolant temp. guage not working

I have replaced coolant temp sensor in the front of the intake manifold and the temp sender in the passenger side head but the guage still doesn't work. I haven't checked continuity on dark green wire that runs to temp sender in the head yet. One thing I thought was weird is that the temp sender is a two prong sender but their is only one wire in the connector. Is that normal?

I thought the temperature sensor has 2 terminals and the temperatur sender only has one. I could be wrong but then again, the person who sold you the part could be wrong. What about the old sender, did it only have one terminal?

I sold myself the part. I have worked @ Schuck's Auto Supply for almost six years. old and new parts are Identical and direct cross over from OE #'s on original. The plug in connector has a specific shape to it so that it won't fit into other sensors. I also wrapped the threads of both sensors in teflon tape to provide a good seal. I am not sure that I should have done that or used some sensor safe permatex or just thread sealant....

Good thing I didn't call the partsman names....lol
I suppose the teflon tape could cause a problem, if the sensor uses the head for a ground?

that is exactly what I was thinking possibly not getting ground. But on the other hand the original sender did NOT have teflon tape. But it could have still been a bad sender.

And don't get me wrong, I may sell parts but I am still no master mechanic by any means. I would say I have decent general knowledge on most systems, still with LOTS to learn.

I would remove the teflon tape, the GM Service information states that you should not use teflon tape or any other type of material since the threads are designed to be self sealing so that the part is properly grounded.

I'll take the tape off and see what happens. I am also going to check continuity on that first couple feet of wire attached to the sender. We shall see.

Did anything come back?