[hgiv]

I was reading some posts about temp sensors. I have 69' Firebird 350. When I got the car it had a 2 post unit installed. One wire comes off the alternator and one goes to the dash?

At some point I messed with it and a post broke off. That got me wondering if i should have a single post?

Either way I replaced it with a 2 post since that is what was in it. I put the wires back on as they were. When you start the car the temp light comes on. When it warms up it goes off. I've never overheated so I can't speak to other end. I'm guessing this isn't correct? Coolant level is fine.

[Kenth]

You will have to use the post R on switch that closes the circuit @ 246° to 266°F for the dark green wire.
Terminal G (not used) opens the circuit @ 129° to 93°F.

HTH

[hobbygto65]

On my Catalina the two post sender was used when you had a cold engine light on your dash it would go out after your engine warmed up.

[hgiv]

So I guess I'm still a little confused. I don't have a "cold engine light" but is the 2 prong sensor working properly or not? The light goes on at start up and off at temp. Sounds good... assuming it would go back on when overheating?

[Kenth]

[QUOTE=hgiv;6267802]So I guess I'm still a little confused. I don't have a "cold engine light" but is the 2 prong sensor working properly or not? The light goes on at start up and off at temp. Sounds good... assuming it would go back on when overheating?[/QUOTE

If you put the dark green wire on switch terminal marked R you will be fine.
The TEMP indicator lamp will light up at "start" and off as engine starts.