On my 2000 ford ranger, the plug that snaps into the coolant temperature sensor, there in on one wire that goes in with another hole for another one but its not there. Should there be two?

https://schematron.org/2000-ford-ranger-25l-gem-wiring-diagram.html

Here is a site, but it has to be downloaded.

You may have disconnected the wire on the sensor.it's close the the thermostat.Check this out. 1995 ford ranger coolant temperature sensor

Looks like you need to replace the coolant temperature sensor for the computer. This will make the engine run rich all the time. You can simply check it with a scan tool with live data capability. With the engine warm read the engine coolant temperature. My guess is it will read very cold even with the engine warm. If so replace it and the truck will be running like new

http://www.autozone.com/autozone/repairinfo/repairguide/repairGuideContent.jsp?fromSearchPage=true&pageId=0996b43f802c551c&partName=Engine+Coolant+Temperature++ECT++Sensor&partId=0996b43f802c551c I f your coolant temperature is normal and no leaks from water pump,then it could be the coolant temperature sensor,real easy to replace.I will send another link of the part.

Automobiles: 2000 Ford Escort ZX2 4-cylinder 2.0L MFI DOHC

NOTE
The "left" side of the engine is the driver's side.

The Engine Coolant Temperature (ECT) sensor is a thermistor (a device which changes resistance or voltage as temperature changes). The sensor detects the temperature of engine coolant and provides a corresponding signal to the PCM (Powertrain Control Module - aka "the car's computer").

The ECT sensor is mounted in the following locations (small Ford engines):

1.8L engines: in the cylinder head
1.9L engines: threaded into the heater hose inlet pipe
2.0L engines: at the left rear of the engine

2.0L Zetec Engine

(1) Partially drain the engine cooling system using a clean container. If coolant is in good condition, retain for reuse.
(2) Disconnect the battery ground cable.
(3) Disconnect the electrical wiring connector from the engine coolant temperature (ECT) sensor.
(4) Remove the retaining clip and the ECT sensor.




Fig. 1 Escort ZX2 ECT sensor - The retaining clip is removed (at the solid arrow). Withdraw ECT sensor by gently wiggling/pulling in the direction of the dashed arrow.

To install:

NOTE
Coat the ECT sensor O-ring with clean coolant prior to installation.

(1) Replace the retaining clip and the ECT sensor.
(2) Connect the electrical wiring connector from the Engine Coolant Temperature (ECT) sensor.
(3) Connect the battery ground cable.
(4) Refill the engine cooling system. An inexpensive plastic "Radiator Funnel" will help with this task.

From your description it sounds like your engine is overheating. Make sure you have enough coolant in the radiator and the coolant reseviour. Check your hoses, radiator, and waterpump for leaks. Have your thermostat replaced if it needs to be. If you can't get hot air from your vents when the engine is heated up it most likely means your water pump impeller is broke and it's not circulating coolant.

replace th air idle bypass valve this is located on the throtle body and has 2 screws with 1 plug with 2 wires to it

The single wire sensor for the gauge is located in the engine block directly below the #4 exhaust port.

The coolant temperature sensor is nearly single handedly responsible for turning on the fans. It should be a three wire sensor. One wire goes to the dash to provide temperature information on your dash, one wire provides a signal to the PCM for coolant temperature information and the third wire is the ground or low reference wire.

If you open the hood, look to the right side of the engine bay, just to the right of the upper motor mount and just to the left of the air filter box, you will see the upper radiator hose. Trace that hose to the engine and that end is connected to the thermostat housing.

If you look just below there on the lower intake manifold, you should see a brass looking device with a connector on it. That is your coolant temperature sensor.

Now, if you plan on replacing this yourself, buy the new sensor. Look on the threads, if it has a red coating on the threads, then it already has thread sealant on it. However, if you want to put on some teflon tape, it wont hurt anything.

Disconnect the electrical connector and use a wrench to loosen and remove the old sensor. Now have the new sensor within reach. Once the old sensor starts to come completely out, pull it out with one hand, use a finger on the other hand to plug the hole.

Then grab the new sensor, put it in the hole that you have plugged with your finger as quickly as you can. If you do it this way, you'll not loose very much coolant at all and probably wont have to bleed any air out of the system.

Hope this helps out.

This video shows the speed sensor and its location for a 2000 ford ranger xlt. It also describes the problems a bad sensor can give.