Temperature guages

[julians]

Following on from my overreading guage. I've had a multimeter on it now, and at full deflection I am getting a resistance of about 80ohms from the sender. The range of the sender is apparently 240ohms to 20ohms (full deflection).

 

Does anyone know what the caterham water temp sender full deflection value should be (96 car on smiths guages), I'm guessing around 40ohms, as I've tested the oil pressure sender and at full deflection that takes 40ohms(ish).

 

So it looks like I have a duff guage, I presume I'm right in thinking that if I just get a resistor inline with the temp sender of the correct value I can bring the temp guage back into line again.

 

Julia