It is a 1997. Yes, there are two ports -- one to the left and one to the right of the housing. The plugs are not interchangeably. The sensor on the left has only one metal prong, and the one on the right has two metal prongs.

 

you're right.. you are going to hafta pull the one that sends signal to the dash.. on those years, one sent to the dash, the other to the pcm.. they combined functions in 98

 

Okay, just pulled the stat and about to put the housing back on. Let's see what happens...

 

I'd be willing to bet this is your problem. In any case, good luck.

Oh, and if you're interested to know exactly how a fan clutch works (and better understand why I think it is your problem), I've edited my previous post to include a description. Its really quite an ingenious little device.... though it (like anything) does have its design flaws.

 

Well, well, I have learned something with the stat out; it is running cool now. Not even half way between 130 and 200. I also turned the plug around that connects to the temp. sensor. Someone tell me, did I put the stat in correctly. Here is a picture of it. Does the picture show how it should be installed?

 

yup.. spring or barrel (depending on the type of stat you've chosen) buried in the engine, with the point up..

 

So, it was in correctly. What's next? Could turning the plug around on the temp. sensor been the culprit? Should I install the stat again and see what happens?

 

was the engine truly warm (it would feel like a bog) or was the sensor lying to you?

if that stat was tested, and checked out- I'd give it a shot.. Like I said earlier, it's my guess that one in five are bad right out of the box.. could be you were bitten- but if it checks out, give it a shot..

how long are you running it to get to halfway between 130 and 200? And this is without a stat at all? reaching those temps should take a long while on an idling engine with a healthy cooling system and no stat... like, ten to fifteen minutes at least..

 

Real possibility you just have an air pocket. Was there coolant below the stat when you took it out?

 

I was under the impression that the temp sensor plug would only go on there one way... but, if you could put it on there wrong, then yes, swapping the + and - would cause your truck to say "what the f@#k?"

Putting the stat back in (after its tested out) would be the next logical step to determine what the problem was.

If you have not done so already, now would be a good time to grind that m@#$%$f^%king tab off to ease stat installation (or just cut it off with a hacksaw like I did).