I have a 1985 Firebird with a 305 V8 that I bought back in July. The water pump blew out and in the process of replacing it I ran into a problem with this thingy.

It connects to the top of the water pump and connects to a hose that goes to the heater core and also has a connector for a pigtail which seems to go to a relay by the battery which I think controls some kind of electric fan that kicks on whenever the engine reaches a certain temperature. I broke the 2 prongs on the "sensor" part of it during removal and took it to a couple of parts stores. No one knew what it was and I was told that they had never seen anything like it on a Firebird before. Also one of the guys who looked at it took it apart and said that there wasn't even a sensor part on the inside of it so it wasn't even sensing anything at all?

Also, the new water pump I installed has some threading in it already that prevents me from putting this thing back in without removing that first. Kind of makes me think that maybe this part isn't even supposed to be on this car.

So what is it? And where can I get a replacement for it?

 

I don't believe its factory either....I've seen people make these before. Drill/tap a heater hose fitting for a 1/2" NPT and use a Corvette (circa 1982) electric fan temp switch. I thinks its close/open range is 238/228 or so....fairly high IMO. I actually have a few of them along with the proper 2-cavity connector also.

 

If you have the switch in the passenger head, then you can ditch that. It's not used. If you don't have the switch in the head where it's supposed to be, then someone did a hack job and put that in it's place.

 

Yeah, I don't know why somebody would go through the effort to install that switch-one lead gets an engine ground, the other is supposed to trigger a relay to turn on a fan. Its just so much easier to keep it a factory type setup.