Hi Guys,

I just brought my first Ford Ranger 2010 model on Tuesday. I noticed that the temperature gauge is broken. It jumps straight up to normal operating temperature even when the engine is cold.

What sort of risk is there that this vehicle had been overheated?

How soon should I get this fixed?

The radiator fan turns on when I turn the car on.

I had it checked out by a mechanic and he said it was fine but he didn't know about the gauge.

Is there a chance I brought a dud car?

Cheers,
Tom

 

If the 2010 Ranger is like the earlier models, it will have two coolant controls; one is a "sensor" and one is a "sender". The coolant sensor is used for the ECU so it can detect engine temps for things like when to set the idle down on a cold engine start, and switch over to other engine sensor readings for fuel/air mapping.

The coolant sender is what controls the operation of the dash coolant gauge. Either this sender is bad, the wire from it to the gauge cluster is bad/shorted, or the gauge itself is bad.

On my 2000 Ranger, I'm able to test the sender/wiring by disconnecting the single wire to this engine sender, and grounding it. With the key to on (not starting engine), the coolant gauge will peg all the way hot; with the ground removed, the gauge needle will be parked on the coldest point. This tells you the gauge and wiring are good, and the sender is bad.

 

+1 ^^^

Here is a thread with pictures of parts on 3.0l engine: Ranger 3.0L Component Locations - Ford Truck Enthusiasts Forums

The ONE WIRE "sensor"(sender) is the the one you want to check.

You say "The radiator fan turns on when I turn the car on", has someone installed an electric fan on your 2010 Ranger?
The Stock fan is driven by the "fan belt" so spins only when engine is running.

 

It appears that the 2010 3.0 does use an electric cooling fan rather than mechanical driven fan. The schematics shows it uses a cylinder head temperature sensor that provides data to the PCM. In turn the PCM controls the fan relay. The relay should be located in the battery junction box under hood. The cylinder head temperature sensor has two wires, violet/brown and green/white.

The engine coolant sender for the dash gauge also has two wires (yellow and green/white). However, both appear to receive and feed data back to the PCM. I would have to assume that the PCM then sends the gauge signal via the smart junction block low current board to the gauge.

 

Good info thanks

 

The 3.0 was not an engine choice for 2010. It is a 4.0 or 2.3

 

Either way, the 4.0 and I believe the 2.3 still used a sendor and sensor for the coolant; one used by the cluster gauge, one by the ECU/PCM.

The OP of this post may want to update his profile, as this is what shows up in his posts:

I am: Tom Jones
Join Date: Dec 2014
Location: Jones
Vehicle: 2010 Ford Ranger
Drive Type: 4x2
Engine: 3.0
Feedback: 0 / 0%
Posts: 1

 

Agreed. So he does not get wrong info for different engines. I wanted to let him know he has a different engine then what he is showing on his info.