Ford Fiesta finnese temperature gauge not registering

[SUR]

Heating system seems to be working normally but the temperature gauge is not registering the engine temperature. Can anyone please point me to the Temperature sensor I need to check & replace or other checks that is needed to be carried out.
Thanks

 

[keyplayer]

You need to locate the temp. gauge sender. (The temp. sensor operates the fan). This depends on which engine you have. ie zetec, endura or diesel.

 

[SUR]

Thanks for the reply.

The engine I believe is Endura. OHV, Car is S reg(98)
Last year there was a problem with the temperature gauge moving near the red hot region and the fan not comming on. I repaced the CTS sensor which is located at the back on the Left side under the inlet. The problem was cured.
The car has not been used much for a while and then noticed the temperature gauge needle just went near/above white band below normal, when hot although the heater was blowing hot air ok. Then the Temperature gauge needle reading stopped indicating the Engine temperature altogether!
Could the CTS sensor have gone faulty again?
Ther is also a connector/sensor with gren or red ring in the heater pipe on the back. what is this for?

 

[keyplayer]

Yes that is the unit you want, nothing to do with CTS. Assuming all your other instruments are functioning ok, disconnect the sender wire and earth it against the cylinder head, (ignition on). If the gauge needle then moves you should replace the sender unit. If not, post back.

 

[SUR]

Are you refering to the sensor in the rubber heater pipe which may be faulty?

This sensor is refered as Coolant Temperature gauge sender(as referenced in Haynes manual) on Endura-E engine.
Suggests removal of the rubber Heater pipe assembly to replace the sensor.

I disconnected the connector on the sensor and when non-sensor end was shorted and when ignition turned on, the Temperature gauge shot up to the High(Hot) position which I assume indicates the Gauge is ok.
At ambient the Sensor reading reads open circuit. Does that mean this sensor (with red connector housing) could be at fault? if so does it have to be a ford part?
and does this sensor control the needle position depending on the Water temperature?

and the CTS(Coolant Temperature Sensor) below the Inlet manifold is providing the reading for the ECU for controlling the Radiator Fan when overheating?

Would appreciate your advice or any other checks I should carry out!

 

[keyplayer]

Are you refering to the sensor in the rubber heater pipe which may be faulty?

This sensor is refered as Coolant Temperature gauge sender(as referenced in Haynes manual) on Endura-E engine.
Suggests removal of the rubber Heater pipe assembly to replace the sensor.
!

Yes, that's the one. IIRC you only need to disconnect it from the cylinder head end so you can lift it for access.

I disconnected the connector on the sensor and when non-sensor end was shorted and when ignition turned on, the Temperature gauge shot up to the High(Hot) position which I assume indicates the Gauge is ok.
At ambient the Sensor reading reads open circuit. Does that mean this sensor (with red connector housing) could be at fault?

The earthing test alone proves the sensor is faulty. Your gauge is fine.

if so does it have to be a ford part?
and does this sensor control the needle position depending on the Water temperature?

I'm not sure if there are pattern parts available, but the Ford one is not expensive, should be less than 20 pounds. And yes this controls needle position.

and the CTS(Coolant Temperature Sensor) below the Inlet manifold is providing the reading for the ECU for controlling the Radiator Fan when overheating?

Don't think the ECU is involved, it's much simpler than that. Water reaches certain temp., and CTS switches fan on. And vice versa.

No other checks required, you've almost certainly diagnosed your problem. Just follow through the manual. You may want to renew hose clip on reassembly, check condition. Take care not to kink the hose and DON'T overtighten the new part. Don't forget the antifreeze and check for leaks!! (And keep an eye on everything for a few hundred miles). You should be fine, it's not too bad a job!! Besta luck.

 

[lib319]

Sorry to resurrect an old thread but can anyone tell me how to do this exact same job on a 1997 Ford Puma 1.7 zetec s.

I need to find and replace the temp sender because my temp guage is reading past the redline even when the engine isn't running and the ignition is at position 2. I've been told it is either under the coil pack (although I think this is the location of the temp sensor) or (more likely in my opinion) on the water pump housing.

I think there is a difference between pre and post 99 models of Puma in that the ECU informs the gauge on post 99 models (with the digital odometer) and the sender informs the guage on pre 99 models.

Thanks for any help.

lib

 

[lib319]

Help!