87 Mustang cooling fan woes

The cooling fan on my 87 Mustang has been hard wired to run when ever the key is turned on. Previous owner thought he was a mechanic AND an electrician, was neither. Haynes manual says to hook up a 10 ohm resistor between the coolant sensor wire and a ground and turn on the key. Temp gauge should read in the “Hot” range. Perform similar test with a 73 ohm resistor and the gauge should read in the “Cold” range. Auto mechanic and I played with a multimeter an the gauge didn’t do anything. Book says that if this test fails, it’s either the gauge or the instrument panel resistor.

Where is this mysterious resistor?

What exactly is your problem? Overheating, not heating up, gauge not working? There can be two or three temperature sensors, make sure you are working on the right one.

Why the new post? Did our answers from the original post yesterday (http://community.cartalk.com/posts/list/2133027.page) not do anything for you? Did our advise seem that bad?

Your post is very fuzzy because I’m not sure if the problem you’re trying to solve is a gauge problem, fan problem, overheating fault, or all a combination of all of them. And the only thing worse than a Haynes manual is a Chiltons.

There is no mysterious resistor hiding anywhere on the car. The resistor is the temp gauge sending unit, which is a variable resistor.
If the gas gauge works and the temp gauge does not then it’s going to be either the gauge sender itself or a connection fault between the gauge and sender.

You’re referring (in the first post) to using an ohmmeter and setting it on the 10 ohm scale. Surely you’re not trying to apply a 10 ohm load with an ohmmeter?

And the gauge temp sender should not be confused with the engine coolant temperature sender, which is a completely different animal.
And many Fords do not even use a sensor for the cooling fan. It’s operated by a module that is controlled by the ECM.

If this sensor connector you’re playing with has 2 wires then you’re probably dealing with the wrong part.