Overheating light ON but cold engine

[alex171515]

Hi everybody,

I have a new issue on my Puma.
Since few days I always have overheating light ON .. but the engine is cold.
This is not a "real" heating problem, I gess electrical ... caused by corosion.

Do you know what make the light On ? Which sensors ?

Many thanks.

 

[grogee]

I'm assuming it's the coolant temperature sensor in the cyl head somewhere - but would have thought that would also send your temperature gauge into the red as well with ignition on.

Had a Volvo once that I thought was overheating but turned out to be temp sensor.

You could try disconnecting the sensor and see if it makes any difference to the light and temp gauge?

 

[alex171515]

Hi and thanks for your reply.
I tried to disconnect the water temperature sensor, the one close to the gearbox on the left side of the engine.
I started the engine and the fans was working on high speed directly ... I guess it work perfectly, I can try to change it but not really sure it will solve the problem.

 

[grogee]

Hmm that sounds like it's working properly. What does the handbook say about the warning light? Does it have a second function?

 

[CherryVimto]

Please check this as I could be wrong.. but I think there may actually be 2 coolant temp sensors.
One is under the coil pack.. disconnecting it will force the radiator fan on to full speed.

The other sensor I think is towards the other end of the engine... but again, please verify this before taking my word for it..

 

[alex171515]

Hi, I don't have the handbook, so that 's why I want to know what trigger this light.
On the part where we put the coolant, I don't find any sensors.
On the website where I usually buy the parts, I see that there is 2 type of temperature sensor, I will find the other one and try to disconnect it.
In the picture attached to my post there is the 2 type of sensors, the number 2 is the one that I found under the coil pack.

 

[DOH]

Hi Alex

The Number 1 sensor above is next to the other sensor i.e in the same area of the cylinder head.
It is easier to see with the coil pack removed

Number 2 sensor controls the gauge needle and also when the electric fan switches on .

I have yet to see the dash temp light on my car , however if you pull off the connector iirc its a black 90 degree bullet push on connection. then if you earth that wire to the engine block with the ignition switched on it will probably put the temp warning light on , confirming your current installed sensor is faulty.

Ensure to get the correct sensor listed for your engine as they often operate at different temperature ranges and can be identified by the colour of the plastic, in this case above being green.

 

[PhilLew]

It's been a few years since I had a Puma but I don't remember it having an overheating light. I thought they all just had a needle gauge?
So I looked up a dash layout image and it doesn't show a temp light. Is this the same dash as yours?

 

[Wild E. Coyote]

Only the older, analogue instrument clusters have 2 temperature sensors. The newer cars with digital odometer (PCM TAPE and DIVE) have only one coolant temperature sensor as the coolant temperature needle is run by PCM instead of the sensor directly. If the IC is like above (PCM MUFF and DUDE) it will have additional coolant temperature sensor under the coil pack.

 

[alex171515]

I checked today, I have a old puma ^^
I tried to disconnect the number 1, I found it under the number 2 and nothing happen.
It shoulb be the root cause of my issue :-D
I buy the 2 sensors and I will try and let you know.
Many thanks for the answers.

 

[DOH]

Only the older, analogue instrument clusters have 2 temperature sensors

I have a Digital dash car , however my 1.7 engine still has both sensors fitted. I maybe wrong, but I think it was fitted purely to fill the hole in the engine, to seal off the coolant used for when the cars first had the analogue dash i.e. It serves no purpose now, if the car has a digital dash.
This is also the case with the front door pillar switches that aren't wired in for the interior light. They are controlled by micro switches in the door lock mechanism itself, which involves a full strip down of the door to change!

 

[alex171515]

Hi, I can send you some pictures when I will replace the sensors in the end of the week when I will receive the parts.
The sensors are very close, the number one is hidden under the coil pack.

I remove as well the speedmeter and I make a DIY thing to connect the light for the doors, I clean with alcohol the door sensor because of the corosion.
Ford didn't put the wire for our puma.

 

[alex171515]

Hi, today I receive the parts and I change the 2 senseors but still have the problem ...
I will check the wiring tomorrow or after, if you have some others solutions I am really interested :roll: :roll: :roll:
Many thanks

 

[PhilLew]

Hi, today I receive the parts and I change the 2 senseors but still have the problem...

Is it this light that is on?

 

[alex171515]

Hi, yes this is this one.

Today I tried to connect better the sensor because connexion was not so good.
Now connexion is OK, tested with multimeter but still have the problem.
I will try to check the air conditionning because I saw on some website that it can make this problem.

If you some ideas ...

 

[alex171515]

One other information : I connect my OBD soft on my puma and I've got nothing

 

[PhilLew]

That light is for the windscreen washer level not the water temp. fill the scren wash and it should go off.

 

[YOG]

Hi, yes this is this one.

Today I tried to connect better the sensor because connexion was not so good.
Now connexion is OK, tested with multimeter but still have the problem.
I will try to check the air conditionning because I saw on some website that it can make this problem.
If you some ideas ...

I don't understand either, as PhilLew said, the item in the red circle is the low washer fluid warning light!

Diagram

• YOG
• Apr 23, 2020

Wash Bottle Warning - Copy

• YOG
• Apr 23, 2020

 

[alex171515]

Ooo :roll: :roll: :roll:
I thought it was the overheat light ...

I checked and I don't find any sensor on the coolant tank.
Do you think this light is trigged by a sensor ? Does it was the sensor number 1 on my previous message ?

 

[PhilLew]

If filling the tank doesn't make the light go out then:-
10D968 is the part number for the low washer level switch according to this.

https://ford.7zap.com/en/car/57/no/0/1833/16633/72431/