My temp gauge barely gets off the bottom indication mark.

My first assumption was the temp sending unit, so I changed it out, but the problem still exists.

I was looking in my maintenance manual, and it says to ground "THE" wire to the temp sending unit with the ignition switch on (engine not running). Well, there's TWO wires to the sending unit, which one is it? Doing this will make the gauge max out, it's supposed to anyway.

 

Which sensor did you change... the one on the water pump or the one on the head? The one on the water pump only feeds the PCM, and has two wires to it. yellow for signal and black for ground. Can't remember whether the sensor on the head for the gauge has one wire or two, but I think it has two. The gauge will show max temp when there is no resistance between the signal wire and ground. That is why they suggest you ground the signal wire, which will be the wire that isn't black.

Did you check the sensor resistance vs. temperature with an ohm meter? There's a chart of temp vs. resistance in my ScanMaster writeup. .

 

Does the sensor look just like the one in the water pump? Hmm, I didn't know there were two sensors, I just changed the one in the pump. Which head is it located in?

 

It's in the driver side head, basically between the 1st and 3rd spark plugs, cant miss it really.

 

Is it identical to the sensor in the water pump? If so, I'll take my old temp sensor that came out of the pump, which is still good and put it in place of the one in the head.

 

The sensors are not the same (at least in part #) and the one in the head only has one wire (though the connector may look the same as the other one).

 

OK, I'll go down and pick one up at the parts store tomorrow. I kind of wondered that after finding it with only one wire and the other has two. Thanks guys.