Temperature gauge

The temperature gauge in my 98 F has not worked since owning the car. I have just changed the sender with no change. I checked the connection to earth and the gauge jumps into life, so I am confident that the wiring is good.
There are two connection prongs to the sender but only one wire to the connector. Does it mak any difference which way round these are connected?

:welcome2:

There are two separate temperature senders. One with two connectors is to the ECU.
One with a single connector is for the temp gauge. It sounds like you might have the wrong sender unit.

Hi thank you for the suggestion . The gauge sender that I removed is identical to new one. Unless someone has been there before of course and fitted the wrong one. The one that I can just about see between the plumbing. I am wondering if I have a duff new sender.
Should I have a resistance reading between a connector prong and the body of the sender? I checked prior to fitting and could not get one.

If in doubt you can check the operation of the new and old senders with a multimeter on Ohms range whilst holding the tip of the sender under a hot tap to view the change in resistance.

To clarify, with a clearer picture.

There are two separate temperature senders. One with two connectors is to the ECU.
One with a single connector is for the temp gauge.


The upper, usually brown or black sender has two active pins and is connected to engine management.
The lower, usually black or blue, sender has one active pin and is connected to the temp gauge.

The connector, single wire, you have mentioned is for the lower sender. It will show fullscale deflection on the gauge if earthed.

Hi David. It is the lower black one that has the single wire and the one I have changed.

Peter.m wrote:

There are two connection prongs to the sender but only one wire to the connector. Does it make any difference which way round these are connected?

The plug should only fit one way round. What is the part number of the sensor you have fitted?
Gauge sender is YCB.......
ECU sender is MEK..........

Thank you for your help. The replacement fitted is MEK000030.
My plan of action is to contact Rimmer's and make sure I have the correct parts and will replace both sender units.