Temp sending unit question

[topdown4runner]

The temp. sending unit on my 87 4Runner with 22RE seems strange.

The female spade connector is centered in the plug.
The male spade connector on the sensor itself is offset and does not line up with the connector on the wire.

The wire has 12V and when I jump it to the sensor, I get a clicking relay sound at a connection on top of the valve cover ( I do not know what this relay is for )

On the temp guage, when I start the truck, the temp reading is at bottom. After a few seconds, it jumps to the 1/2 way mark. It never goes up or down.
It does this no matter if the wire is hooked up to the sensor or not.

Obviously, I have either the wrong sensor, or someone used the wrong plug from somewhere else in the engine bay at some point.

Why does this plug trip the solonoid when grounded?
Is there supposed to be 12V at this wire? The engine does not sound different when the solonoid is tripped.

Am I even in the right spot for the temp sending unit, or is it somewhere else in the engine?
My manual shows the sending unit a little different ( maybe for a carb. engine ? )

BTW, this is not new with the temp guage, it was like this when I bought the truck 2 yrs. ago...

 

[turboSR5]

Not sure about the connectors, I would need to take a look at mine. But, the solenoid in your picture is your auxillary idle up (forget the scientific name). It will boost your idle higher when you are at idle and either turn on your AC or turn the wheel while at a stop (power steering).

This is more than likely your problem that you descried in your other high idle post. If it is constantly on then your idle will always be above normal rpm.

 

[topdown4runner]

O.k, thanks for identifying the part.
Problem is...the male & female spades do not touch when it is plugged in, so it is never activated.
When I jumped the two, the solonoid "clicks", and is active. No change in rpm when this is done btw.

 

[topdown4runner]

Is the temp sending unit wire supposed to have +voltage at it?

I thought it was supposed to vary the resistance to ground through the sensor.

 

[fourwd1]

Yes, the sending unit is basically a variable resistor with one side connected to ground. 12V is applied to one side of the gauge and the sender is connected to the other.
You can check the sender with a DMM, from terminal to ground it should be ~140 to 175 ohms at 60* C and 2~ 0-30 ohms at 115* C.